what are some 1v1 champions in the late game that are not autoattackers or range champions

this is pretty much it

LUL LULULULUULULULULULULULULULULULULULLULULULLULULULU

huehuehuehue

There are no 1v1s in the late game. At least, there shouldn't be. That aside, though, Darius and Illaoi are the only ones I can think of. Both of them are mostly ability focused and deal damage at mid-range. Perhaps Sejuani could be a good option too. As you'll note, they're all juggernaut styled champions. This is natural because late-game it's best to be able to deal and take damage.

That's... not a thing. If you are good close up to others, then why not be attacking them? If you don't need to attack, why get close?

Do you mean someone like Ekko or Fizz? They're not AD, but they have to land autos to get their damage in.
Malphite/Amumu/Moakai/Sej/Zac/Rammus/Naut? Most of those can take 1v1s if they're even in gold and have the moves, but 1v1 isn't really their strength.

If you're asking if there are good late-game champs who deal most of their damage with very short range, single-target, non-AA abilities... No, that's not a thing. Zed or Rumble are probably the closest ones that come to mind, but they don't really hyperscale like a Jax and they have significant ranged poke.

is the ultimate answer. You can literally stand there, do nothing, and destroy the ADC that's dumb enough to hit you.