With community member accounts, a confirmed email address is a wonderful thing to have. Yes, you can use it for notifications and to contact the member. But just as important, it’s an account security issue. If the member ever has trouble accessing their account, confirmed contact information might be the only way for you to give them access to it again.
The way this normally works, with online communities, is that a person signs up and is then told to check their email. You send them away from your community, and take them out of the process of onboarding. They are motivated to join your community, but you are holding them back, for that email confirmation. Hopefully, in their inbox, there is a message waiting with a link they can click to activate their account. I say hopefully because, sometimes, these get marked as spam. But if it’s there, if they find it, if they click the link, then they are back to your community with an active account.