I did withdraw ERC20 tokens worth about 300 USD and the transaction fee was about 26 USD... In percents, it's unacceptable... One would think transaction fee should be about 1% or less of the amount being transferred for it to be accepted.

My own cryptocurrency has transaction fee of 0.01 that doesn't change dynamically depending of the amount to be transferred. It can't go lower, because the cryptocurrency only has two decimals, but the exchange rate between my cryptocurrency and USD is so low that even for small transfers, 0.01 is not worth too much, as smallest usable amout is about 60.00.