I have to say, I do love PostGIS. But for "this data absolutely cannot be lost or its game-over", I'd go MySQL every time. I can and have debugged MySQL replication on zero hours of sleep. It's entirely possible Postgres 16 is the better choice for new projects today, but I haven't had the time to try it out in production yet.
Man...times have seriously changed if that's the case. Good for MySQL to improve enough to get that recommendation.
* undetected hard disk in array fails
* battery in array controller fails
* disk fills up
* dubious backups, with no point-in-time recovery
* extremely poorly written SQL queries
* poory configured MySQL (in oh-so-many ways)
The top three (at least) would lastly cause replication lag, which would eventually trigger an alert. ... And yet we never lost a cluster. (And we far a lot of them!)
My team sweated blood improving processes and tooling, and then I spent a 6 month stint on database clusters (switching to GTID based replication and rewriting the ops config code so that they were all consistently configured and monitored).
Occasionally we'd get a new senior hire insist that PostgreSQL was a necessity, so we'd stand back and let them produce a proof of concept that stood up to the types of failures our MySQL clusters dealt with regularly, without waking oncall up at night. And it was always a bit of a joke by comparison.