Invite only? Google in beginning was the same, hence why I never made a gmail account and stayed on yahoo, which allowed me to easy move from it to protonmail 1

Invite only? Google in beginning was the same, hence why I never made a gmail account and stayed on yahoo, which allowed me to easy move from it to protonmail 15 years later. Also Facebook was the same, only students were allowed in beginning, which meant I never made a Facebook account either.