It has never been as easy as today to see slow / shitty queries life.
Open telemetry, tracing and grafanasupport with k8s you basically get it running in a day.
But with performance it's always the same issue: people apparently do not think about it and the optimizations necessary are often: enable query statistics, finding the query in code and either fix/add an index or slightly rewrite your code or add some kind of cache (query, etc).
The last time I analyzed a slow query apparently no one before me spotted the huge memory footprint of that PostgreSQL query and focused on why it runs slower in one region vs the other.
You know the '10x developer' myth?
Yeah if you still look like a sheep after working in it so long and thinking about architecture and performance is still not second nature for you...
I'm slightly cynical because I love performance and optimizing it but 99% of those issues are no issues just people not knowing enough about their tools.