Making it system-only still isn't ideal. It then requires a full OS update to push updates to microg/playservices, cannot just update the app components if vulnerabilities are found in the wild.

I would like if there was stronger privacy laws or antitrust orders that force Google to open their service provider API's so people can choose alternative location/push providers, but this doesn't seem like it will exist soon.

For many users, it's going to be the best usability compromise to use minimal play services and use apps that don't send content over the push networks (signal is like this, element can be configured this way).