Unfortunately F-Droid sometimes distributes outdated software with security vulnerabilities. This happened with Fennec (Firefox variant), not sure what the reason was. I switched back to Firefox + Google Play after that.
Yes F-Droid is too slow unfortunately. The reason I added obtanium to my mix was because F-Droid version of RedReader was so old it didn't work with Reddit anymore. And I couldn't figure out why or if there was an ETA or what and someone mentioned obtanium.
https://f-droid.org/docs/Reproducible_Builds/