I'd recommend using Libredirect if you're on a Firefox-based mobile browser. It can configure redirects to alternate "frontends" that will serve you much more agreeable HTML (though because we live in hell, it will usually still involve antibotting out of sheer necessity. But I accept this.)

For Reddit, my choice for now is safereddit. If I need to view a Reddit link on mobile and old Reddit is blocked as it sometimes is, I just swap the domain to safereddit.com.

For Twitter, my choice has been xcancel for ages. I have no idea how that manages to stay up in spite of Twitter's hostility but it is a Nitter instance that seems to just work.

You can also run these frontends yourself, too, but I assume it requires accounts.

(edit: Also I hope it goes without saying that I don't really have any specific trust that my activity is necessarily more "private" with these frontends, although honestly if I was forced to bet I would have to bet that they are much more respectful to my privacy than Twitter or Reddit are. I just use them for functionality.)

Good luck fellow traveler. If there was more to do in real life, I'd probably had thrown my phone into the ocean by now. I'm about halfway there in spite of the lack of many appealing third spaces.