I've heard a perfect word to describe this before but I was not diligent enough to write it down; never thought I'd actually have a chance to use it. I just remember it was a fairly advanced/academic term to describe simplifying something. I do remember bits and pieces of the original sentence I heard it from, context is how adult hobbyist lego collectors critique certain lego releases:
"I'm not particularly fond of this set, because, as you can see, the build of the car has really been _______. They are clearly trying to make this set more accessible but it's come at the cost of quality and sophistication."
The way the word I'm trying to think of differs from "simplified" is that the word I'm trying to think of has a connotation of being designed for a younger audience, maybe like juniorized but that's not a word nor is it the academic-sounding word I'm sure was used.