.xyz is soaring because it was cheap registration, and cheap renewal fee. So many .xyz domains are developed by small end users. This is becoming interisting to Big Companies, when seeing .xyz actually worked well in internet. Google also make algorithm that make .xyz well indexed, because it used by alot of people.
.co, .io, .ai was marketed well but the price are very high. The renewal cost also very high, so they are consider premium domains for small part of Startups.
.us is cheap, renewal fee is also cheap. But geo limited. Google search has algorithm that make .us only for US search. So .us is limited for US business or domain hack.
Might be .cc, .one, .vip can be the next tlds those are largerly adopted like .xyz. The sign is already seeing, as Chinese Internet prefers to use them, like .xyz 6 years ago.