If you'll settle for a millennial's opinion, websites used to show more information and load more quickly and didn't crash or have front-end bugs or gobble up all your memory. Idk how much of that is due to JS itself and how much is just the fact that the internet now is just five or six bloated corporate megasites though.

As for the question in your OP, Twitter intentionally cripples their site for anyone not logged into an account, so I use Nitter because otherwise I can't read the site at all.