@M66B had already said several times in the past that there would be too few users under GitHub/F-Droid for whom it would be worthwhile to continue the project.
Yes, this is true. Play Store gives visibility to this app that it wouldn't otherwise get without it.
If you want to play ball in Google's stadium, gotta follow their rules, regardless of whether you agree with them or not, and regardless of whether their policies are illogical or not. The problem with Google is that they have become so powerful that they can essentially dictate policies, with very little power on the part of devs/users to do anything about it if they disagree. I believe it's not a good thing for any corporate entity to wield too much control. The power goes to their heads.
In the end they are a business, with their profits being the most important thing to them...not users, and not devs. To that end, they collect mountains of data about us, then use it to try to sell to us. I guess it's all just a matter of how much influence we are willing to give them in our lives. Don't ever think they're the benevolent good guys, they aren't. The "do no evil" motto went out the door long ago.
Others may choose to go along with whatever they say, but I personally make it a point to only make limited use of their services, avoiding them if there are better alts. And to not give them more data if it's not necessary.