I have used almost two dozen different exchanges till now (2012-present), and I have seen withdrawal fee ranging from BTC0.0001 to BTC0.0015. Perhaps the highest withdrawal fee that I ever paid was with the Yobit exchange (I think that they have reduced the fees now). Nowadays I don't care much because I am not doing much trading. And I am mostly using peer-to-peer platforms to convert my cryptocurrency to fiat (or the other way around). The problem is that many of these exchanges had this withdrawal fee of 0.001 BTC or 0.0015 BTC in 2015 when the price of Bitcoin was just around $250. The prices have risen by almost 40 times from that level, but most of the exchanges haven't reduced their fees.