People get stuck on the adrogen receptor being the problem, causing the lack of further gains.
Personally i dont by it at all. I dont believe the receptors get desensitized at all tbh. I think the more likely possibility is that inhibitory proteins, on of which being myostatin, increases as a compensantory mechanism to limit growth.
This is due to it being very dangerous to be able to grow without limit. This is why you need yo lower the dosage of all compounds, which in return lower myostatin follows.
Once these inhibitory proteins decrease enough you blast again, allowing for more growth. Obviously the more muscle you have less you can gain each time, since those proteins will remain higher with increased muscle.
The reason why blasting and cruising works better than just chronic high dose cycles is, muscle cells dont die just fat cells. The only shrink, unless there is an extreme circumstance. The muscle memory thing is real, any cell wants to be in its biggest state thats its ever been in. It just need the proper stimulation to do so, and if we cut gear they will TEMPORARILY shrink. However, once you get back on high dosed gear the the return to there largest size VERY quick. Then now you have lower inhibitory proteins limiting growth, for a bit before they raise again, allowing for new growth to happen. This causes a new set point for both on and off gear.