threads.net is currently blocked. You can see a complete list of blocked instances here. There was a discussion about this when threads first announced plans to federate.

Would sooner federate my naked flesh with the contents of a blast furnace

I'd like to have access to the content without having my current stuff swamped. I guess the question is how the algorithm treats an instance with a lot more activity. If it overwhelms, I can just go get a different username and monitor them separately.

Also how does Threads deal with sublemmys? Seems like this might be more of a question for Mastodon.

I learned something new today that mastodon.social (I could be remembering this wrong, it's one of the big instances) is run by, or adjacent to in some way, Cloudflare. So that kinda changes my perception of who's already in place on the fediverse. I haven't done any research into this but, this factoid was presented as CF basically already being in a position to hoover up user data, parse it in corpo ways, and do with it what they please. Meta/Threads is obviously fuelling the awareness that big players can continue to swoop in and do this.

It's kinda the way fed is designed. If a community (or group of communities) wanna fight this it'll take cooperation and collaboration. Think whole neighborhoods of huge cities using bylaws to keep big box stores and fast food chains out. Or rural communities fighting pipelines and freeways from coming through, or huge suburb development plans, etc.

My two cents.