A strike at BT is threatened after it emerged this week that the company may be drastically slashing its final salary pension scheme. If BT takes that step, it will be a fundamental breach of the contract that existing workers signed up for, and industrial action will be inevitable.

But will BT workers (and Royal Mail employees in a similar position) really go on strike? Some fascinating figures this week from the Office for National Statistics chart the near total death of the British strike. In 2016, working days lost to strikes was just 322,000, a tiny fraction of the 29m in 1979 and the all-time high of 162m in 1926, the year of the General Strike. Even during the second world war, when emergency legislation in effect banned strikes, the number of days lost to industrial disputes stood at about 2m a year.

The number of strike ballots in 2016 was the lowest since Electoral Reform Services started keeping data in 2002. In 2006 there were 1,341, but last year this fell to a record low of 488.

Just as remarkable is who is going on strike. In the past, miners and transport workers made up the biggest number. But in a sign of just how much industrial action has collapsed in the UK, the single biggest strike last year, accounting for 40% of days lost, was by junior doctors.

Yet there persists a mindset among some that unions are too powerful. At the end of 2016, an Express headline read: “Swaggering union bully boys must be brought to heel”, claiming that “a mood of reckless militancy is spreading across Britain”. Nothing could be further from the truth.

The reality is that Thatcherite legal changes, such as the end of secondary picketing, the collapse of union membership to just over 6 million – down 4% last year alone – and the rise of globalisation has massively weakened the prospects for industrial action.

Many, of course, will welcome this – no one wants a return to the “winter of discontent” – but the result is that labour’s share of the national cake has shrunk significantly, while the proportion going to profits and into the hands of the 1%, – has risen.

The internet has played its part, too, channelling vast sums to a few hyper-profitable companies and individuals. Others say reduced militancy is about the restructuring of the economy; although miners, dockers, shipbuilders and car workers made up only about 5% of union membership in the 1960s and 70s, they accounted for up to half of all strikes. Those industries, bar the carmakers, have all but disappeared.

Yet it’s still remarkable how few worker rebellions there are. Economic theory suggests that with unemployment so low – back to the levels of 1975 – and the stock market at a record high, fuelled by record profits, workers should be able to negotiate better pay. Instead, wage suppression continues.

Why? Because with unions crippled, and “new economy” jobs in lowly paid retail and distribution sectors, employers have been in a position to offer almost whatever terms they wish. The ONS figures show the total number of stoppages across the entire retail, accommodation and food services trades in 2016 was one. Yes, one. The ONS could not even calculate a ratio for working days lost per 1,000 employees, as it was so infinitesimally small.

Our economy has millions working in precarious contracts and false self-employment. Union organisation is likely to remain weak, although at some point the reservoir of cheap labour for employers will dry up, not least because of our exit from the EU.

During the election campaign, Jeremy Corbyn has been tirelessly presented as a figure that will take Britain back to the strike-stricken 1970s. In the era of globalisation, that is hugely unlikely – but measures to improve the bargaining position of workers are now long overdue.

• This article was amended on 5 June 2017. The previous picture showed miners striking in 1937 but carried a caption suggesting it was during the 1926 General Strike. This has been changed.