Which leads to the same issue as Bitcoin, Git and other open services - costs of managing are so high, that there's going to be monopolization in the hands of the one that can attract the most resources... and even when the financial costs aren't high(hosting Git or a mailserver on your home router/server/NAS is not expensive), the time costs start to take a toll.

There's going to be a mental barrier to these things - paying $9 per month for a managed Mastodon instance is mentally way too much. I pay for Google One, to not think about storage and mail management... and get many perks with it.