I have run my own server for the past 20 years. I don't spend a lot of time maintaining it but managed to enable SPF, DKIM, etc as they rolled in. The most disruption I have faced has been changing connectivity providers and IP ranges. But even then I have been able to insist on being allowed to relay and removed from blacklists consistently. I think it is important some of us do it even if most people live off big provider webmail.