Just quit beta then
Is there a way to access OLD Chess.com?

Just quit beta then
I'm not talking about beta I'm talking about the completely different interface that was used in like 2016

Well, there is the internet archive 'wayback machine': https://web.archive.org/web/20160401165925/https://www.chess.com/
As an example I picked the home page from a random day in 2016 and was able to click on an article by IM Silman, and the article was displayed in the old format, etc. So... you can kind of tinker around with the old website through that archive.
But if you're asking about playing games through the old interface, I seriously doubt that will work through the archive pages. I don't think there is a way to wind back the clock on the basic game user interface, which seems to be what you want to do.
But, for nostalga's sake, if you want to look at the site (not play games) under the old format, the internet archive/wayback machine is the way to go.

The funny thing is going way way back to see the chess.com page displayed before chess.com started formally as a website. "coming soon...!" etc. It's kind of funny to see the domain parked before the site opened up.
Beware of the internet archive, once you go down that rabbit hole you can spend many hours looking at how things used to be.
I want to play on old chess.com just for nostalgia's sake, I think it was called version 2.0 or something? Anyway I remember when version 3.0 came out you could access it through the tab at the bottom of your profile on the main menu, is there a way to go back to it? Or is it gone for good