Many apps that are on F-Droid are also on Google Play, but there are exceptions. Gadgetbridge (smart watch connection app) warns that the Google Play version is unofficial and unaffiliated. An unofficial app might be upstream compiled without modifications, but this opens users to potential supply chain attacks from the uploader and Google.
This is the first top-level comment that hints at the main criticism against systemd. systemd is increasingly difficult to replace as time goes on. I like and use systemd because it has a fast boot, but I wish the project was developed in a more modular way that had choice built-in. It is instead developed as the way that everyone should systemd instead of alternatives. This philosophy gets in the way of distributions that want to provide alternatives (Devuan, Gentoo, Parabola, etc.). Some of the sysadmins I work with closely use Devuan and follow development. I hear the patch set around bypassing systemd grows in size and complexity each year which is worrisome for choice.
threads.net is the domain. You can get a head start and block any IP addresses associated with it using the firewall of your choice.