I'm not sure what exact device you're using, but on iPhone 12 Mini, old.reddit.com is borderline unusable, very different experience compared to if you could access r/all like before via the actually usable web+mobile version, a comparison: https://imgur.com/a/AVGjjCN

Anyways, the end result has been I don't use reddit at all on the phone, so kind of ended up being good for me anyways.