Ask sg united, the Ragin Stajins, 85 FG% or any of a bunch of other teams how easy it is to stay up once you make it here.
I wouldn't say it's difficult to survive up here if you're somewhat prepared, but that preparation has to be taken up a notch and you must have the forethought of being and remaining competitive and need continued internal growth if you actually want to be a good Naismith team. I've remained stagnant for 2-4 seasons because I didn't have the necessary continued growth. I've been training 2 players who capped ridiculously early for 2-3 seasons and have had zero growth. My player Cazzola has 1 pop (2 maximum) in the last ~35 (?) weeks of 48+ minute training and my player Rabaud has 3 pops in the same time frame.
I knew 85 FG% and Weather from another game and they both recently quit; part of it may have been because of college, but at least some of it had to do with them peaking very early like myself and not wanting to rebuild. Weather's arena was also puny so that factored in.