For example, something that is too complex for your comfort level, a security concern, or maybe your hardware can’t keep up with the service’s needs?
Backups. Cloud services like Backblaze B2 are so cheap for the durability they offer, it just doesn’t make sense for me to roll my own offsite solution with a Raspberry Pi at my parents’ house or something. Restic encrypts everything before it leaves my machine.
Password manager- it’s too important and it’s the thing that has to work for me to recover when I break something else. I’m happy to support Bitwarden with a few bucks a year.
Email- again, it’s mission critical and I have a habit of tinkering with things and breaking them. And it’s just no fun. The less I need to think about email, the happier I am.
That’s what “1” in the “3-2-1” backup strategy stands for, a true offsite backup (preferably continent where you do not reside) For “2” I would still deploy a local offsite at someone’s house for quick disaster recovery.
Downloading your 10TB data from B2 (or even requesting a tarball HDD from them) is costlier than recovering from an offsite backup facility within an hour’s reach.
A public Matrix server. Its just a never ending black-hole of ever increasing storage requirements and the software is too buggy to not become a maintenance hassle.
I do run a Synapse server for bridging purposes, so I am not just talking in theory.
XMPP is safer and lighter anyway
And so damn easy to self-host in general. Ejabberd is batteries included down to offering stun/turn for audio/video calls, Erlang is just unrivaled when it comes to hot reloading so updates are effectively zero-downtime (unsurprising considering all the business critical environments it’s deployed).
At first (and especially because I went with Matrix originally) I wouldn’t think of self hosting all my instant messaging, but in retrospect, ejabberd is one of the easiest services I’ve got to maintain. I highly recommend everyone to give it a shot, especially to all the matrix refugees to whom it was a surprise/disappointment.