Main Keyoxide dev here. That's an interesting suggestion, could be very useful! I don't have much experience with Open VSX or VS Code Marketplace. Do they have APIs for accounts?
You wouldn't need to use your email as account id. The account id could even be completely random, as long as you manage to link back from that account to your key (in case of twitter, a tweet with the key fingerprint), anything works! Just add a link to that account to your key.
With regards to decentralization: keyoxide doesn't hold the proofs. Your key does. You can take your key to any verification system, whether it is keyoxide website or some CLI tool or an app, and have that verify the proofs. Yes, you do need to trust the service. But that's where the open source and hopefully one day, network effect comes into play. If enough knowledgeable people trust it and talk about it, then less-techy people might one day too.
In the end, what is important to note is this: keyoxide is just an implementation detail. If soon a different service becomes much more popular and used, the "decentralized identity proofs" ecosystem still wins! I would love to see apps get developed where anyone can at the press of a button verify online identities. That will be the next big milestone.
TLDs do still matter. Part of the indieweb movement is focused around not relying on search engines. The TLD is half of your domain so some consideration is needed.
Personally, I could have gotten yarmo.nl, given that I'm Dutch. I chose yarmo.eu because I'm fairly certain my future is not in the Netherlands, but elsewhere in the EU.
I also wouldn't want a TLD that support Britain's continuing colonial rule and defense of acts against human rights.
I'm not saying all should boycott .io, just the (open source) developers who wish their products (and domains) to reflect their core principles.
I'm sorry to hear about that experience, that's not IMHO the way it should be. That leaves you the opportunity to take your knowledge and opinions elsewhere. This would not be possible if you got banned from Twitter.
It saddens me that every time I see a fediverse-related post on HN, it gets inundated by people who don't "get it" and that is to be expected: fediverse is not Twitter and everybody gets Twitter. That change in mentality is not easy.
Fun story: massive influx of users from India recently and the timelines got flooded by posts indirectly asking: "what is the way to fame here? How do I get followers?". Fediverse doesn't work like that. You just… talk with others. There's no "you and your followers". There's "us".
Analogy: you are not in a metropole. You are in a village that is extremely well connected to all other villages. You do not need to shout to be heard.
I'm on a FOSS-focused instance. We talk all kinds of stuff and FOSS is one of them. I have my Home timeline where I follow all the people I want to hear from (both my instance and all others). I have my Instance timeline where I'm basically guaranteed to read interesting stuff I can reply to and meet new people who also considered this instance to be their haven. And the Known Fediverse timeline… Well, it's fun to browse but come on, imagine a timeline of all tweets on Twitter: mostly useless.
Choosing the right instance also involves choosing the right moderators for you. Mods can block other instances. If you don't like what the mods do, change instance or start your own community. After all, it's not Twitter, the people decide how content is moderated, not a for-profit company.
That's the fediverse for ya. Hope to see you there!
Mastodon is holding up just fine and growing rapidly, the atmosphere is much nicer and every few weeks, there's a massive influx of new users whenever Twitter is upsetting its user base.