I’d like to use regional rail but when flying is cheaper and faster (even with security checks), it’s a relatively easy decision to not even consider it. Hopefully these improvements help reduce the price of fares.
In the NE corridor the train station is downtown, so you need to factor in the price of getting to the airport, checking in, board, taxi, land, taxi check out, then travel from the airport to downtown.
It is a pretty competitive offering, even with the aged infrastructure, in my opinion the only real deal breaker is on longer routes where yes planes are faster and often cheaper, but the biggest issue is freight train priorities which can make train timing imperfect.