Because modern anime has a lot of mass produced trash. It's no ranma 1/2 or utena or Saint seya or macross, Gundam, cowboy bebop, outlaw star, cat's eye, lupin iii, etc... there are ton of well produced anime before 2000 that are actually good. Some are confusing messes but at least look amazing. I tried watching bleach and the newer stuff is just so boring and cringey.