Arnie doesn't deny he was on steroids either. He "just" says he only used them while they were still legal. Whether that is true or not... Well.
But the impressive part of Arnie's physique from a modern standpoint is the symmetry and attention to detail, not really size. We have steroid-driven monsters like Ronnie Coleman that makes Arnie seem like a starving child these days...
I think the bigger problem with bodybuilders as an ideal is that most people don't understand that Arnie didn't look like what he looks like in most of his published photos for more than a few minutes on stage every year. E.g. at his peak shape, yet cut as much as possible, dehydrated, pumped, oiled, artificially tanned, and flexing to the max.
That's not what Arnie level bodybuilders look like if you meet the on the street, or in the gym...
I like to point people to Conan, as in the actual movie rather than the posters. That was Arnie in the kind of shape that let him win Mr Olympia in 1980, yet if you look at the movie rather than the posters and pictures most people are used to seeing of Arnie, his seems big but his shape doesn't seem all that unachievable - that's the difference that competition prep makes...
People also misjudge size of bodybuilders in pictures massively, I think, and seem to believe they're huge giants mountains of muscle. Consider that Arnie at his peak was roughly 105kg, at 6', and with a 34" waist. There's tons of untrained guys larger than that - bodybuilders like Arnie just looks massive because of their shape and low body fat.
Of course most people still won't achieve Arnie's physique, especially not without steroids, but you can get "close enough" to his day to day appearance much easier than most people think.