I've been hosting my own email for 20 years now with several ISPs over that time and have never had issues with port 25 being blocked. Maybe it is more common outside the USA?

Most recipients these days are also validating more using SPF/DKIM than IP blocklists. If I ever come across a recipient that is blocking my IP I have a relay that I can use for that specific domain.

All else fails, hosting your own email services with a cloud hosting provider or colocation service is still better and provides more privacy/security than using one of the big public email providers.