The co-creator of The Simpsons, Sam Simon – who died on Sunday, aged 59, after an appropriately pugnacious battle with cancer – truly was a remarkable man. He was a living George Bailey whose largesse touched thousands of lives, both human and animal, from rescuing homeless dogs, feeding unemployed families, donating millions to Save the Children and campaigning against animal cruelty.

His larger-than-life existence also included spells as a boxing manager, neighbour of Elvis Presley and collector of fine art (he had a Rodin in his back garden).

The reason he was able to live so generously was thanks to a sweet deal he pulled in 1993 when he left The Simpsons after just four seasons as its chief writer and showrunner. As demonstration of just how desperately the two other key players – Matt Groening, whose drawings spawned the show, and legendary producer and director James L Brooks – wanted to get rid of him, he negotiated a package where he would get a percentage of revenues not just from the shows he worked on but for all future episodes of The Simpsons too. The deal also included merchandise: dolls, DVDs, comics, lunch boxes, movies and all.

Why Brooks and Groening disliked Simon so much is not entirely known. Silence was part of the deal and a few barbed tweets aside, Simon never went into great detail, but his severance package earned him a minimum of $20m every year – money he took great pleasure in spending.

But what exactly was Simon’s contribution to The Simpsons? Does his era mark the golden years of the show, or has his role in the creation of TVs most beloved dysfunctional family been exaggerated?

Nostalgia can easily distort reality. The internet didn’t even exist for most of us when the first series launched in 1989, born out of Matt Groening’s short cartoons which were used as bumpers between the ad breaks on The Tracey Ullman Show. Back then there was no online snark or cyberbullying; people bought books from bookshops and records from record shops, and TV was largely bereft of zombies, science teachers running meth labs and mothers of dragons.

Good stuff stood out. Way out. Before The Simpsons, there had never really been an adult animated TV show. The Flintstones (based on The Honeymooners) and Top Cat (on Sgt Bilko) were seen as kids’ shows, but The Simpsons managed to operate on both levels. For all the fact that Homer, Marge, Bart, Lisa and Maggie had yellow skin and lived in a cartoon world, they were also the closest representation of actual American family life that had ever been allowed on TV.

Sam Simon visiting a chinchilla farm after he financed the purchase of the facility by Peta. Photograph: Mike Blake/Reuters/Corbis

As revolutionary as it was then you would have a difficult case arguing the merits of the first season of The Simpsons today, and it was here where Simon’s mark is most obvious. He had a hand in writing every single episode and created many of the supporting characters (Mr Burns, Chief Wiggum, Dr Hibbert) who still exist today.

Back then, The Simpsons was very much a sitcom in animated form. For Simon this was a perfect storm. His early career included drawing sports cartoons for newspapers, then working as a storyboard animator before he broke into sitcoms writing for Taxi, Cheers and The Tracey Ullman Show. According to John Ortved’s book The Simpsons: An Uncensored, Unauthorized History, Simon gave The Simpsons its voice. He hired “the Manhattan Project of comedy writers”. He introduced both highbrow and lowbrow cultural references - there weren’t many allusions to Helmut Newton on mainstream TV before The Simpsons.

Simon helped conceive the opening titles and flesh out the Springfield universe. He thought of gags like Homer’s fantasy Land of Chocolate. It was Simon who kept the writing tight and policed Groening’s wilder suggestions. Ortved demonstrates some of the conflict on the show by recounting an idea of Groening’s whereby Marge would shake down her beehive to reveal that she had rabbit ears. Fortunately, Simon talked Groening out of it. It’s hard to imagine we would still be watching it 25 years later if he hadn’t.

In the blaze of publicity which surrounded the Simpsons’ first two seasons, Simon’s name was barely mentioned. Instead the only story the press wanted to hear was Groening’s rags-to-riches lucky break. No doubt it ate away at Simon, spending every day in the writers room while Groening, according to Ortved, kicked back in his office inventing new merchandising ideas.

As for The Simpsons’ golden season, Simon’s last is certainly up there (A Streetcar Named Marge, Marge vs the Monorail and Mr Plow are among the show’s very best) but the truth is that it hit its creative peak in the three or four years after he left. Not that those seasons would have been possible without the team he created and the standards he set. Today and certainly since the 2007 movie, The Simpsons is very much Groening’s kingdom.

Asked before his death if he still watched it, Simon said “if I had to watch it to cash my cheques I would”. It still has the ability to make you laugh – last week there was a great gag where Burns sneered at his neighbour Richard Branson – but rather than the lean, anti-authoritarian sitcom Simon planned, it is a fantastic machine. An unstoppable force that will continue to house homeless dogs and fund vegan meals for many, many years to come.