Link -> https://www.reddit.com/r/fossdroid/comments/hfabrf/whats_the_difference_in_installing_a_foss_app/
1. #fdroid builds everything from source. This means that the apk from F-Droid will correspond to the source code. Also, F-Droid's build environment only allows other free dependencies, so no proprietary libraries (especially things like ads and Google Play Services integration). The build process is transparent and easily replicable if you so wish to modify or build it yourself. There are no secrets.
2. The other thing about #fdroid is that it does not track its users, even metadata collection is kept to an absolute minimum. That's why you download the entire (metadata) repository locally every time, so they never see you looking at individual apps, they don't know your locale/system language, etc. They just see you downloading apps. #googleplay, of course, tracks everything.
@javalps this is a lot of useful information, but it doesn't answer my question.
@deafhobbit Ok. So, in a nutshell, for an average person, "it doesn't make a difference". But it does for people who wants to #degoogle their life.
@javalps I am somewhere in between those two, so I'll probably switch to the fdroud versions over time.