The 20th year of the Garma festival was in some ways a muted affair compared with previous years – neither the prime minister nor the opposition leader made an appearance.

Perhaps they would have found this year’s theme of “truth telling” a little discomfiting.

Last year Garma was fired up. It had hope and enthusiasm for the Uluru Statement from the Heart and its call for a constitutionally enshrined voice to parliament, a makarrata, and a truth-telling process – a truth and justice commission. It had recently been endorsed by the prime minister’s referendum council with their recommendations to government.

But between then and now, Malcolm Turnbull has rejected the proposal, claiming – despite the voice’s proponents and developers saying otherwise – that it was asking for a third chamber of parliament, an unsellable referendum prospect for the Australian people.

Gumatj leader Galurrwuy Yunupingu said he cried to hear the Uluru Statement read out. Nothing had changed, and the deadline he gave last year to Turnbull – the eighth prime minister he has worked with – and opposition leader Bill Shorten to come together and find a solution had long past.

With the voice to parliament proposal stalled in a new joint select committee, Garma’s key forums and fireside discussions debated the other ways to reach the end goal: substantive change for Aboriginal and Torres Strait Islander people in Australia.

Some, like Noel Pearson and Megan Davis, push on with the voice, while some have turned their efforts to treaty – already under way in some states and territories. Others talk regional agreements and legislated solutions. All stressed the importance of a truth-telling process.

But the most affecting perspective came from William Tilmouth, a man of Arrernte descent and the former central Australian chair of Atsic, the now defunct Aboriginal and Torres Strait Islander Commission.

As children, Tilmouth and his siblings were stolen from their family and sent to Croker Island. He lost his Indigenous language, culture and identity. He has seen many friends and family who suffered the same trauma pass away.

“They’ve died in the streets of Darwin alcoholics or murders or suicides,” he said. “Sorry meant nothing to me.”

In a speech on Saturday, Tilmouth said those who were stolen had lost their claims and connections to native title and land rights, and he feared the same would happen again with treaty and constitutional reform.

Tilmouth said the Uluru Statement’s request was clear, but told the crowd “it is up to all of us to think seriously about what we are doing, why we are doing it and how we are doing it”.

William Tilmouth at the Garma festival. The former central Australian chair of Atsic said he wants the voice to parliament proposal to go ‘full steam ahead’. Photograph: Teagan Glenane/Yothi Yindi Foundation

“It’s something that the Aboriginal people who have privilege, who have language, who have land, have to start bringing everyone along instead of leaving people out there bitter by themselves, wallowing in a deep sense of loss,” he told Guardian Australia.

“It’s up to those people who have those attributes to bring those others along and not just to think of themselves but to say ‘come one you’re my brother, come with me’.”

Tilmouth said the problems of stolen generations weren’t a big part of the dialogues leading up to Uluru.

“I knew that the side that was missing needed to be expressed – sure, I’m proud to be an Aboriginal person and I’m proud of who I am, but I know there are deficiencies and limitations in how I express that,” he said.

“Most people got up and spoke in language first and then spoke in English. It made me feel inadequate that I could not do that, but it was not something that was a choice of mine.”

Despite his concerns, Tilmouth said he wanted the voice to parliament proposal to go “full steam ahead”.

“But don’t leave people behind, bring them with you.”

Sean Gordon, the chief executive of Darkinjung Aboriginal Land Council, listened to Tilmouth’s speech and was overwhelmed by the memories it prompted of his and his late brother’s experience in foster care.

“What we’re proposing with these models is to recognise, not just doing the voice, not just doing the treaty processes through a makaratta, but a truth-telling, and the truth-telling isn’t about dividing us, it’s really about understanding our collective history, good and bad, and then bringing us together,” he said.

“The truth-telling aspect allows William and others to identify their truth and to say this is how I feel and I feel I’ve been cut out of these processes of native title and other things, and how do we start to rectify that?

There was potential for people to be excluded again, Gordon warned.

“Right now we have 16,000 Aboriginal kids right across the country who have been removed from their families. Those kids will have a similar story to tell.”

On Saturday morning Pearson told the Garma crowd constitutional change was a “life and death” matter and warned against the pursuit of treaty and what he labelled the “hobby horses” of health and education service delivery before a constitutional voice.

Others respectfully disagreed. Labor senator Malarndirri McCarthy, Yanyuwa woman and member of the joint select committee, said both could go on together.

“I don’t think that one jeopardises the other. If anything it galvanises that sense of hope,” she said, adding that regional areas deserved to be involved in change at local and state levels as well as federal.

In the past year some state and territory jurisdictions have begun moving towards treaties with Indigenous nations, although South Australia’s has been abandoned by the new Liberal government.

The Northern Territory signed a memorandum of understanding with the four major land councils at Barunga earlier this year and is seeking a commissioner to lead the process.

Vincent Forrester, a traditional owner from Mutitjulu at the foot of Uluru, said a treaty would not hurt anyone. “It will enhance Australia as a nation.”

He called for action on behalf of a community that had been “stitched up” at the time of the federal intervention.

“Let us make our own mistakes. Because look what the mob in charge now have done,” he said.

“The record is there for all to see. When we go for treaty … we must have access and membership of the three tiers of government.”

John Christophersen, the deputy chair of the Northern Land Council, said if treaty were signed tomorrow “the world will go on”. “But Australia will wake up, not losing 230 years of colonial rule, but gaining 65,000 years of history.”

He also warned against an “escape clause” being written into whatever was established that might allow individual politicians to abolish it, as happened with Atsic.

Last week former federal minister Amanda Vanstone suggested abolishing Atsic had been a mistake, an admission noted by a number of speakers at Garma.

Gordon said this was why whatever the representative body turned out to be, it must be enshrined and protected in the constitution.

“We can’t move forward as Indigenous people on the back of someone making a mistake or a politician not liking an Indigenous leader and ‘therefore we’re not going to continue’ to support that structure.”