As time passes by, with bigger and bigger blocks (hopefully), more and more transactions will fit into a single block, reducing the need for high fees (or at all?!)
I do not see nor want a future where miners have such power as u describe, it's counter productive imho; not the way it was created to be
The fee, although small from individual transaction point of view, is huge from all the transactions combined point of view. Imagine that average transction is 0.5 btc, and every one is totally fine with 0.2% of fee, and a large block in future can handle 100000 transactions per block, then the fee collected by miners per block will be 100 bitcoins, is there any problem?
The biggest benefit of bitcoin monetary system is total limited money supply. This character will never change even the miners are collecting more fees. Satoshi has indicated that in future mining fee will replace the block reward, but he never said the fee should be lower than block reward, maybe he has envisioned a future of 100+ bitcoins per block fee