> up "oh, do you work at <company> too"?

Oh boy, I had many of these conversations and especially non technical people never grasp the concept, I had some cases where they demanded to change it and use a “real email like gmail!!”, one time I bought shoes and the store guy asked me the email to signup for whatever, so I read the shoe’s name and added the custom domain, gave me the the look as if I am bullshitting him. Another at a government connected agency and she thought “I work there because I have the agency email” despite it is the alias not the domain.

But similar to OP, few times I found the service is leaking my email, or they got compromised who knew.