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?
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.
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.