It is not just bored, but the websites feel old for some users. Also, the high resolution and size of screens affects designs that used to work well. Supporting mobile for a website will break it how it used to work. I do think material leaves too much empty space and fills it up with nothing to make it "easier" for the user. However, I will say material designs sometimes take away functionality for the users sake (and not in a good way).

I would like to see this applied to an actual mobile or desktop application. It would make for a great experiment.