There's an interesting wee parallel with alts there. For whatever reason after all this time .com is still the gold standard despite it being three largely meaningless letters. The only reason why is because the collective has decided that's how it's going to be. Tokens.co is available for $999 right now. Is one solitary M worth another $499,001 to you?
For me, hell no! But some companies are pretty loaded, and I do see their point in paying an extra 499,000 for an extra M, it's all about brand image and being the first company in the game. When people think of a domain, it is hardwired in them that they usually think of one with a .com, and having a domain like tokens.com is worth the money, especially if they are a new start-up flush with funds.
Domains like that and blockchain.com were going for $200-$300k when this whole space was nothing but a fart many years ago---blockchain as we know it today wasn't even a thing back then.
If $200-$300k was paid without there being much of a market for it back then, how much do you think (think logically) these domains are worth today with how this space in general has grown x1000?
If that wasn't enough info, a lot of these domains were paid for largely in Bitcoin.... you can imagine how many coins were needed to acquire these domains with how low Bitcoin's value was.
They look for insane prices, even if the industry/niche is small, and then one day they end up hitting the jackpot when someone or a company with a lot of money to burn goes and picks up the thousand dollar domain.