They also very often don’t understand what’s easy and what’s hard to implement, what’s a real priority vs a nice to have, and have extremely strong opinions against off-the-shelf components and prefer building everything from scratch.

Also: The lesson of “don’t rewrite” from Joel Spolsky seems internalized in the minds of every developer, but "rewriting from scratch" is basically how designers operate by default.

Most of the explosion in frontend development complexity and amount of work in the last few years is because designers are inflating development costs and companies are eating it with smiling faces where complaining that developers are costly and wanting AI to fix the problem.

This kind of inefficiency and inequality in decision power is a huge thing in our industry. The same situation happens with QAs trying to play product and asking for modifications at the end of development that very often amount only to personal opinion and require developers to keep burning political capital to say no to.

I am not saying designers, QAs, PMs and developers should know everything, but when true collaboration doesn’t happen, due to personalities or political reasons, the result and the execution will always be lacking.