That’s extra work, throwaway services are often blocked

Never had any issues whatsoever, it is less work to me than logging into my mail account and confirming my account, but I also like to have a separate account for every service and never use the “login with facebook/whatever else” option.

it also defeats the purpose of having a backup contact in case of loss passwords etc.

That’s true, but if you actually want to be able to recover your password, there isn’t a way around providing your email.