I'm not aware of there being any limits for that, and I think it'd be in the admin panel if it were.

On Reddit I think it's mostly a limitation to try to keep database queries from going too slow as browsing ordered list like these on most databases amounts to running the query and discarding the first X results and returning the next Y results. So the farther you go back, the more expensive the query, especially on really big databases.

On Lemmy, if you run your own instance, I doubt anyone would care if you make a 20 seconds query to go browse really far back. All the data is local. So that'd be an admin setting of some sort.

Yes, here