> So from the perspective of someone who has to actually install, use and frequently update a dozen of Android apps, it is much easier to stick to only using such which do not want internet access instead of constantly having to read a very large amount of changelogs because all software you use is hooked up to the internet.

Even offline-only apps might gain online capabilities. You need to read the changelogs nevertheless.

In the case of Joplin, AFAIR it is offline first when you start it. As it supports various sync options you have to configure one before it will start syncing over the net.

I think the risk of Joplin getting a sync option that is activated by default is about the same as an offline app getting online features.