No, you can do it on all the major providers for either no or low cost.
Disregarding the grandfathered free accounts, own domain is $7.20/user/month on gmail, €5/month on Proton. On microsoft that's business tier feature and AFAIK not supported at all on Yahoo.
alt Hacker News
Disregarding the grandfathered free accounts, own domain is $7.20/user/month on gmail, €5/month on Proton. On microsoft that's business tier feature and AFAIK not supported at all on Yahoo.