Let's ignore all of the preinstalled programs, which are signed by Google and do a great deal of spying.
Do you think the 100 most popular F-Droid apps do more spying than the 100 most popular Play store apps?
Do you think the 100 most popular F-Droid apps do more spying than the 100 most popular Play store apps?
Those are more likely to be outright malware on Play.