I haven't used those in particular but have tried several sites for this and have been very happy with Backloggd, you may want to take a look and see if you like it. It's heavily based on Letterboxd, so if you use that for movies it'll feel familiar.
Gaming
I've been searching for a 'letterboxd for games' for years, and iirc that's partly what Ggapp bases it's site on. I'll absolutely give Backloggd a look though, thanks.
If you are an Apple person, I've been using GameTrack for years. It's great and new features are always being added.
I've been using Backloggery for many years at this point. Not necessarily because it's amazing but I've gotten used to it and it's pretty straightforward to use.
I've been using Grouvee for a while and I'm still happy with it.
Taking a quick look at Questlog, the term "backlog" doesn't seem to appear anywhere, which I appreciate. It's a work term and isn't great for mental health when used with a hobby that should be relaxing.
Looks like their "similar games" algorithm needs work, though.
I just use notepad on my desktop, its so much faster than any app and obviously doesn't require me to be online. These pics are mostly how I format it, though I did move it around in paint 3D since its too many games for a single easy screenshot at 8 font lol.
I haven't ever used a game tracker but I would be open to it. Do these sites typically keep track of games you are currently playing and if so do they have a section for "games that I come back to and play sporadically?" Like Civ games I will spend months without playing then play a few games for a month.
Like, you don't really "beat" some games.