> Rather, let everyone (juniors, QA, non-developers) in the team perform reviews of everyones code, even your senior code.

I think the OP is just saying that juniors should be allowed to participate in the reviews of senior engineer code (not that a junior review alone is sufficient for merging a PR).

I think this is a great way for juniors to get exposure to the complex topics they might not yet understand, but should learn more about.