true, I should have gone more in depth with it, the missing bit is that, assuming the db schema is not completely borked, cores and ram and fast disk on a db get you a long long way, so the tipping point for performance is often when you hit a real scaling problem as a mature company while younger company can get by just purchasing more iops from a vendor, given the current total comp of a full time dba.

of course if one want to get serious on tuning itself all the kind of analyze toolings available in and around postgres are phenomenal, I think on par with those of oracle, albeit my exp there is stuck at 12i of the old times, which makes pg my default choice for any project.