I know Services is available in a sandbox, I didn't think of that, presumably because I view it either with disdan or treat is not an option. There's also MicroG which I've never been interested in trying.

Buy an Android phone that you can flash to change the OS to remove all Google dependancies and use F-Droid to get all of your apps.

I found Bridgy Fed to enable Bluesky to communicate with Mastodon.

It would be no suprise if chromium is more secure but Firefox is more private.