I've only used launchers to avoid enshittification e.g. Google Search box or other proprietary features that I don't want.

I started using them back in the day, when most phones had a very limited launcher. I have used nova for many years, it has a ton of customization options. I'm not sure how it is these days, but previous phones also came with thing that I did not like and could not disable or remove. Like a permanent Google search bar, or the Google assistant being a dedicated page on your home screen.

That was/is the best part of Nova launcher. Highly customizable, but not laggy or slow

What even is it? Is it like fdroid for example?

I used it many years ago, perhaps 10, and started using it again because it allows me to rename PWAs. I have four instances of Frigate running for various locations and now i can edit their name based on location.