The stations are filthy, have poor accessibility, the signage is tattered, the PA systems almost never work, the ETAs are often wrong if they’re even offered. That’s aside from the not uncommon sights and smells of piss in the cars themselves. The bus system is a different crapshoot altogether.
I find it interesting how often when people complain about how poor the experience is, there are those like you who seem to be quite content with maintaining a fairly low standard.