Town Reset?

DivinylsFan​  For what it's worth, I haven't abandoned a save in Sunset Valley for performance or corruption reasons since I switched away from playing on a 2010 Mac, running the macOS version with its 2 GB RAM limit.  That's not to say nothing has ever gone wrong, and I do abandon saves for other reasons, but I don't think the world is inherently unplayable for any length of time.  In fact, it's one of the most stable worlds overall.

What can be a problem is that it doesn't have accommodations for features from later packs, or that adding those features can clog up the town.  There's a reason that the newer worlds all have at least some combination rabbitholes—fewer overall means more space for other things.

There's also the fact that every world has a soft population limit, above which the game engine will start to drag on any system.  I don't know how many resident sims are in your world, and this limit is pretty high in SV from what I've heard, so this may not be relevant.  But letting SP go wild forever is not conducive to long-term saves no matter where you're playing.