Did the same. Blizz changed tanking because it held back dps. The game was actually designed to be all about aggro management. Tanks tried to do as much threat as possoble while dps had to do as much dps as possible while not pulling aggro.
This was discussed by blizz. They changed it and intentionally eliminated the threat gameplay so dps coukd go full ham. They tried to make the tank game be about active mitigation. It just wasnt fun. That is the #1 reason i eventually gave up on wow. Not the only reason. But for sure i stopped tanking, then eventually stopped playing at all.