To me it's not interesring because it suffers from the same issue all the alternatives have. Getting a domain is not prohibitively expensive if you have low st

To me it's not interesring because it suffers from the same issue all the alternatives have. Getting a domain is not prohibitively expensive if you have low standards for the url (which presumably you do if "93736474.xyz" works) So the inevitable result is that a large number of applications using these will be so low effort they couldn't get a much better domain for barely more money, and that will probably end up being a mix of spam, malicious applications, and questionable content. And the end result is everyone blocking traffic from .xyz. Just like someurl@extracheaphosting.com is.