Because shields were seriously op in cyrodlil, the problem was Everyone had 20% damage mitigation, expect Shields were full strength, so someone could spam 10k Shields all day long, against people that have 110 weapon damage, I sat there earlier as an imperial templar, 4 of us were spamming wrecking blow/biting jabs at a sorc spamming Shields.
We literially couldn't even remove his Shields.
My friends left after 15 minutes of it. The sorc couldn't kill me as I just held block and he had very little damage. This is on ps4 so we still have full strength Shields.
It's not Dead, you just can't sit there and hold it, it requires more passive buffs. Before anyone could sit and hold block for eternity, regardless of passives.
Now you're going to need sword and board, and full heavy armor for the total 50% reduction cost, along side champion points you'll get another 20% reduction.
To be honest my stamina bar barely went down, as the sorc spent more time spamming Shields to get crystal frags to proc more than anything. So even without regen I would have been fine, as I would use puncturing sweep inbetween and some heals.
From what I've seen on here, tanks are still doing fine in trials and endgame gear/pvp with blocking.