you are missing a couple things here, both twitter and mastodon allow following “topics” in that you can follow hashtags.
additionally you can federate more content from other instances that no one follows by connecting to a relay.
not saying this entirely fixes the problems you bring up just that there are ways to somewhat address them.
I just set it so it never grabs focus and remembers its location. That was when I click to another tab the PiP window doesn’t take over focus from the browser.