Do they fulfil the same function as Google Keep, of being completely fucking useless?

I really like notallyx from fdroid cause it supports indentable checklists which I use constantly :)

Its a tad jank and unstable at times though

I use fossify notes for small offline things like grocery shopping lists.

Otherwise I use filen notes for things that need syncing across devices.

https://github.com/FossifyOrg/Notes

https://github.com/FossifyOrg

https://filen.io/