Goku leaving the Time Chamber early

Ignoring everything after Z, I think the reason Goku/Gohan left the time chamber early were the diminishing returns. Like Goku stated they couldn’t get any stronger, but I think it’s more attributed that his training partner wasn’t suited to help Goku train and it was getting to the point Goku couldn’t get Gohan any stronger through training. My thoughts since I know the topic of “Goku and Gohan just go back in” is a whole thing. I know it’s ultimately w/e Toriyama writes, but this is just my thoughts when reviewing the arc.

Edit:

Let’s take this a step further, let’s look at the original training with Piccolo and Gohan. Who had the most gains in that three year time span? We see that it was a significant increase for Piccolo for sure, but his statements on Goku vs. Vegeta, the gains are minimal with Vegeta torturing his body in the manner Goku stated is not conducive to training for the entire three year time span.