Well he died around 25 years ago and he was on air from 83-94. I don't know if his show was ever aired in the UK back then.
His story is quite interesting. How he became so big now though? I'm not sure, the internet has a bizarre way of making cult figures out of the most random people. When I were a teen it was Chuck Norris for example. People just seem to capture the collective consciousness of the online space.
I like to think people found enjoyment from his videos because they were something of a tranquil island in the sea of toxicity that is the internet at large. Since 2015, although more likely 2012 if you're of a certain age and a gamer, the online space has really gone to shit. Wherever you fall on the political spectrum, commentators are angry, they want you to be angry, they want you to hate the other side and the opposing views. You couldn't really escape it in 2016 if you were on Twitter or YouTube regularly, and I'm sure the tendrils of division made it to plenty of other places aswell.
Yet there, in the middle of it all, was a kindly man with a soothing voice, who loved what he was doing. His art isn't complex, he's not trying to make any bold statements, but it's accessible. For the time you are watching him, the problems of the real world fall away as you watch him guide you through the creation of his world and he assures you that you are capable of creating your own little worlds, full of happiness and peace. He's that reassuring voice that I think alot of millennials especially were drawn to.