To throw my 2 cents to this.
I just got some pieces of blue gear, to be precise gloves and boots. They were are broker for 10k gold which is nothing these day. So I put them on and went to play some dungeons. Turns out now I'm now immortal. Mechs that one shot me before now barely scratch me - they do about same as normal attacks did before.
I did 2 runs of new shiny hard dungeon AQ, one with my old HO+0 gear and one with these two pieces. First run, let's say I died a lot, we took a long time, but thanks to heroic healer we didn't actually wipe, was fun trying to anticipate boss moves and predict them really like my life is on line (because it is).
Second run ... well I died like one or two times. Why ? I literally fell asleep in middle of my rotation, because I couldn't bring myself to care to block. So this new shiny hard dungeon is about as hard that you could clear it with party of toddlers and, decent healer and 100k gold (one time).
This is unacceptable. I literally don't want to progress in gear, because it makes game too boring. What am I supposed to do ? Make a macro that does 1 > 2 > 3 > repeat, because it can play as well as me ? No need to block, no need to do mechs, just facetank everything.
Please buff literally every dungeon, make them lethal and not a playground for toddlers.