I agree with you on the MSQ doesn't teach that well (anymore). It used to have more difficult content and the side content used to be harder as well. Somewhere along the line a lot of things got nerfed and "easy" and "very easy" versions of solo instances got added. Those solo duties at normal difficulty provide the tools to learn, but if someone fails and auto selects very easy... they're not going to learn.

The example I used was Thornmarch EX (maybe not the best example because it is still technically an EX). It got nerfed so hard that it no longer really teaches any mechanics. It used to actually teach sprouts some easier versions of harder mechanics they'd experience later.