Using a public service like proton or firefox for that has the advantage of you blending in with the crowd, i.e. the service doesn’t know who the account belongs to whereas the service knows exactly that it belongs to you because only you have the top level domain.
In theory … in the real world it doesn’t matter too much because noone will hunt you down.
I guess that it’s no more of a hassle than using one email with your own top level domain.