Just a nitpick, but, this assertion is just wildly, ridiculously inaccurate, if you include PP Mall Garage.
When I first started commuting from PVD just before the pandemic, the first day I drove in and parked at the garage embedded within the PVD train station, I complained to the parking-lot attendant about the prices, and he said, "yeah, don't park here as a commuter; it's much cheaper at PP Mall Garage."
Happily I took his advice; the rates at PP Mall Garage have been unchanged--$140 month (less than $5 a day!)--since summer 2019. It's only a 3-minute (300-yard) walk from the garage to the train station, so it's as convenient as you can get without being a directly abutting facility.
Finally, both pre- and post-pandemic, there have always been hundreds and hundreds of available spaces at PP Mall Garage as late as 9 or even 10 am in the morning. (Though they do generally all fill up at some point in the afternoon; even in the era of Amazon/online retail, it's definitely challenging to find parking at the PP Mall by 5 pm on weekdays.)