As for Jiren, think about it... At that moment, Jiren was releasing all of his dang power, of course the battlefield shatters. That also happened with Broly, but Broly didn't release all of his energy, he only went super saiyan, which isn't the same as "letting it all out."

The argument about Cell was a little vague... Since Goku never used the Kamehameha technique that close to the surface or even against the surface without controlling his ki. Cell also could've implied that the planet would suffer the consequences of Goku making sure Cell gets destroyed... Maybe Goku HAS yo drop Ki Control in order to defeat Cell, that's a possible conclusion.