Is Elder Kai's ritual one of the strongest abilities in the franchise?

[Champa The Destroyer]

My main question is because when he brings out Gohan's potential, it seems like he said that he could've done it longer to bring out more power. Iirc he did it a few more hours than Gohan wanted, just to bring its potential past it's limits. So that begs the question, does it have a limit?

If someone had the food, and kept from going insane, could they spend a whole day in the time chamber getting their potential boosted? Or why don't humans like krillin use it?

[Hulk10]

Simple answer is that the writers chose not to have them use it.

[theherodjl]

At this point, Rou Kaioshin's ritual is just another method of getting stronger, nothing more. There have been a number of convenient ways to boost power seen throughout the series so you might as well ask how come they don't use any of those ones as well? Everyone could drink the super divine water, go to New Namek and have Muri unlock their potential, make a wish on the DBs, find a magician who has an ability like Babidi's, undergo artificial enhancements, and so on but they don't. Everyone just likes improving in their own way rather than relying on easy methods of power growth everytime.

[Lionel]

I'd say it was the most impressive of an array of potential releasing abilities. Yes the Choshinsui, Grand Elder ability, and Babidi's spell each released the recipient's power -- particularly in the case of Babidi's they were afforded even greater power stacked onto the release -- but with the Elder Kaioshin's ability it seemed to propel Gohan to heights that were arguably unmatched by any unfused character at the time. Relative to Goku after the Chochinsui who was an equal to Daimou, Gohan boasted a superior boost on top of no longer requiring conventional Saiyan transformations to access this power. Vegeta needed to transform to reap the benefits of Babidi's unlock. Gohan's was consolidated into one "Ultimate" state.

If you ask me nothing seems to match the Kaioshin's ritual besides maybe Shenron's wish which seems a bit convoluted if you ask me but it is what it is.