Comment by klodolph

Kind of like databases and web servers, then?

I don’t think “categorically different” has legs. I work on the operations & hosting side of applications like this. There’s an operations burden to maintain, deploy, and scale web servers. There’s a burden to rolling out new Linux kernel versions to servers. But we still do it! There would be a burden to running your own Slack, just like there is a burden to running your own email, and people will choose to pay for hosted versions or host it themselves.

And then there are companies and organizations who have strong incentives to self-host to make compliance easier.