The other system you're using that isn't Postgres can also go down.

Many developers overcomplicate systems. In the pursuit of 100% uptime, if you're not extremely careful, you removed more 9s with complexity than you added with redundancy. And although hyperscalers pride themselves on their uptime (Amazon even achieved three nines last year!) in reality most customers of most businesses are fine if your system is down for ten minutes a month. It's not ideal and you should probably fix that, but it's not catastrophic either.

What I’ve found is that, particularly with internal customers, they’re fine with an hour a month, possibly several, as long as not all of your eggs are in one basket.

The centralization pushes make a situation where if I have a task to do that needs three tools to accomplish, and one of them goes down, they’re all down. So all I can do is go for coffee or an early lunch because I can’t sub in another task into this time slot. They’re all blocked by The System being down, instead of a system being down.

If CI is borked I can work on docs and catch up on emails. If the network is down or NAS is down and everything is on that NAS, then things are dire.