I don't mind the Mastodon v5 UI, looks about the same as the v4 one to me. I have the same complaint about both, which is that infinite scroll isn't infinite for me. I only look at my feed around once a week these days, and usually (v4 and v5) I get to the "end" (no more posts will load) before I get to anything I've already read.
Is there an alternative client I should be using to get manual paging, or a URL hack for the official client eg to specify a starting date?
[Self-answer in reply]
Apparently the limited home timeline posts is server-side and longstanding https://github.com/mastodon/mastodon/issues/36168#issuecomment-6592673896 I've probably just noticed it more with less frequent social media checking.
I suppose the solution is to use a feed reader instead of Mastodon to subscribe and read.
Allow for unlimited timeline/infinity scroll · Issue #36168 · mastodon/mastodon