At first Bitcoin transaction fee was minute, now its high.
Ethereum was free before, now without gas ethereum can not be transfered.
Bitcoin Cash now is high and having issues.
I just thought about digibyte. Its cheap and You need 3 to 5 dgb as transaction fee, so variably if 1 digibyte becomes $2000 then 2dgb as transaction fee would be a problem.
But for STEEM its free ever since and it is still free.