Sempa Well, if the permissions are not invasive it should be fine, but indeed; most of these apps are great for privacy.
An app that scans for permissions and/or trackers will give a little more clarity in that regard.
However, using some kind of proxy like TOR or a VPN might give more privacy on top of that, especially if you don't post anything identifiable.
There is no guarantee though, like with most things online.
I use Tusky myself, it has no trackers and very small amount of (necessary) permissions.
Do check trackers and permissions on every update though.