The Japanese were not known for surrendering. There were mass suicides because they refused to be taken alive:

https://www.atomicheritage.org/history/japanese-mass-suicide...

It's not ineffective in all situations. A single soldier, isolated from his group, fighting 10 seniors or children simultaneously, is not going to do well. Plenty of people are killed in the Middle-East from rock throwing.

It's not an implausible hypothesis that an invasion of Japan would have been a larger, and proportionally bloodier, version of the takings of Iwo Jima and Okinawa, two very bloody battles.

Right, but at no point were those the only options (even according to key military figures).

The firebombs the Japanese flew across the Pacific, setting fires in the Pacific Northwest of the US, were largely built by children.

https://en.wikipedia.org/wiki/Fu-Go_balloon_bomb