Since Fall of 2022, there's been a negative spiral within the MBTA. Primarily due to poor maintenance leading to: service cuts, full shutdown of certain lines, and the highest percentage of slow zones in recent history.
They are returning a good chunk of the system back to regular service this Summer, though.
Edit: the slow zones might not be clear on that graph, but at one point the Red Line end-to-end was around 1-1.5 hours slower. Especially bad for commuters.
the subway only runs from 5:30 to 1am (so good luck getting to the airport for a morning flight). also it's been on fire and slow and often down for maintenance