I don't think most users would be willing to pay for domain (and remember to renew it etc) just to create email address.

Also, there are some interesting projects like protonmail, which is great but there's uncertainty whether it will survive in the long run.

@OP, if your email provider is a registered/legit/non-anonymous  business, you should expect they'll notify you well in advance before winding up the business. Otherwise they'll risk legal actions for data loss etc.

ps. agree with LaudaM, totally off-top