Sure. Like everything in life, this can obviously be subjective too. I'll answer all your points :)

4) happy for you, I think it's a problem for who starts designing for the first time.

3) My clients were a lot like "I do not understand anything about these things, do something nice".

2) yeah not a big issue, but I've noticed people who I introduced to UI design struggling trying to use those grids.

1) Sometimes you just not have the time. At least where I work right now, management is a bit problematic (1 full stack developer who is literally burning out). And more precise the design, lesser the iterations :D