I think this was all started when Binance reduced all its withdrawal fee on major coins then suddenly all of this top exchanges followed what Binance did. But still based on what I knew, Binance is the lowest withdrawal fee among all this exchanges. Its a good thing since they knew that bull run will come thats why they reduced all withdrawal fees.
No, mate, it did not start from Binance, rather OKex was first. After oKex reduced the fee, Kucoin, and Binance followed them. I think many exchange already did this to stay in the competition. Because higher withdrawal fee really sucks and most of the trader doesn't like it But now everyone in the crypto space is very happy!