Here are my some of my bad experiences,
In centralized exchange, Poloniex, I was using Poloniex's Platform peacefully for a couple of months,
but when I tried to verify my other account, suddenly when I tried to reload the page it says that
Poloniex blocked my IP address, and that problem wasn't solved for a couple of months and their
support is trash, no response for months.

In decentralized exchange, IDEX, Forkdelta, etc. The first time that I visited their website I was
so confused... yes, their web design is very complicated, I had a very hard time using their platform,
hope they will improve and simplify their tools.