With games, they're are various categories like:

1. Demos I want to play
2. Demos I've played and my opinion on them
3. Demos that I might want to play, but I haven't decided yet.
4. Games that aren't worth putting on my Wishlist, but that I'm not prepared to discard entirely.
5. Games from my wishlist that I'm unsure if I actually want to play and that I need to sort.
6. Games that I haven't wishlisted but might want to.
7. Everything to do with itch.io because their launcher and storefront is garbage.

In terms of manga, I use a database site but there are limitations.

1. There are some I've read one chapter of and saved for later, some I've read nothing of but want to read, and some I'm reading but put on pause because of the release schedule.
2. When it's time to start a new manga, I normally pick out more than one. When that happens I bookmark the list and go back to it after I finished the previous one.
3. There are manga from before I started using a manga database and haven't sorted.
4. There are manga that I've marked as "want to read" but for various reasons am reconsidering.
5. There are oneshots I've read on Reddit and saved.

As for why I don't self-host, I don't really want to buy more disk space in this economy. Also (and more importantly) a collection of pirated manga is far harder to backup than just a database. In terms of preservation, I have so much new stuff to read that I'm not too fussed if something goes away.