I used to do that, but it caught far too much spam sent to random usernames on every domain. Now I have a fixed prefix and do prefix+literallyanything@lastname.me, which gives the same benefits with less spam.

You don't use the simplelogin (now part of proton pass) random or custom address generation? You can use your own custom domain with it.

I've been doing this with nearly every new account as it's normally email or phone which third party data sharing is keyed off of.