Plus they always try to hide how stuff works behind the scenes so that day that upgrade script has a bug and fails, it’s hard to revert to a working stage.

Yunohost is creating backups for apps that are being updated. If update fails, it automatically reverts. Yes, it works, I checked.

those projects get eventually abandoned,

Yunohost is here for years now, and it does not look like it will be abondoned any time soon.