Can you ever quit PEDs and keep the gains with no TRT or HCG, or are you guaranteed to go back to your natty baseline?

And I mean literally coming off everything, no trt, no hcg monotherapy, just completely bare. I know you're guaranteed to lose some size for sure, but do you eventually just shrink all the way back down to your natty baseline? Or is it actually possible to hold onto that somewhat enhanced look indefinitely if your training, diet, and recovery are totally dialed in?