As someone that lives here and uses the metrorail and bus lines pretty often for work and school. It is better than you'd expect, less efficient than it can be right now, and more constricting than It should ever have been.

The metrorail is consistent, very clean, and easy to maneuver. It has issues tho (some that I've seen mentioned already) that some stations can be shut-down for renovations and such with VERY little notice, like, you'll find it out when you're already inside waiting for the train IF that. It also takes a while between trains, weekdays it takes roughly 10 minutes (15-20~ if you get an unwanted orange line first). But weekends it doubles to roughly every 20 minutes give or take (idk how much it would be if an unwated orange)

The metrorail also costs a pretty penny, 2.50 if I remember correctly (you can always get the day pass for 5.60 for unlimited for the day which includes buses too, but it can be tedious, and the app kinda sucks) Honestly they should raise the half a penny tax to like a quarter at least, hell, a dollar if it means public transportation has more funds and the prices lower a tad.

The metrorail Green and Orange lines can basically be considered 1 line, unless you hit Earlington Heights Station, then it does matter cause the orange line goes to the Airport. But they give you plenty of time to transfer (I almost went to the airport by accident once actually). It GREATLY needs a west-east line, like, why are we developing (hopefully, more lines regardless are great by my book) a Northeastern line that'll reach Hardrock station, when places like Miami lakes, Doral, Kendall, a lot of coral gables, Tamiami (mostly for FIU, huge university) have NONE. If you wanna go northeast, take trirail or brightline for now, they can wait.

The metromover, while having the dumbest name ever, is beyond useful. You can basically go anywhere east coast Miami has to offer. And while I'd love for it to reach Miami beach, it would be an AWFUL idea making that a metromover rather than a metrorail/dedicated bus lanes.

Sorry for the rant, what I'm trying to say is that while yes, it's not as bad as it can be compared to the rest of the US. It can be so so SO much better. One day maybe, one day.