So I watched this and I hope they change how gear levels are dealt with. As Krip says, the Legendary you find this level won't be amazing in about 3 more lvls. Legendary gear should only drop rarely and be something you can build a character around, not some throw away item you need to replace 3 levels later
Sacred 2 the gear levels changed on set pieces every 15 lvls or so. Grim Dawn you can find similar armour at lvl 35 and lvl 50.
Both of those give you time to use and enjoy the equipment before it needed to be replaced.
D4 sounds like you constantly need to look at gear to find that amazing upgrade that only works for 4 levels before you need another one.
How they did gear and reduce the items importance and elevate the stats instead, means people won't be looking for the perfect items, but instead want to collect the perfect stats. Less likely to be able to sell those. In 3rd party markets. Blizz tried to take the money with the AH, now they saying no one can have it if they can't
Monsters levelling up with you means no sense of progress, you don't feel any more powerful than you were before levelling up,. if anything you can feel worse as the percentage of power gained by them might be larger than your gains. It should be sane, if you level up during a dungeon, they should be the lower level until after you complete it. Not change level right away.