I have seen in many trading signal telegram channel was promote and use Bitmex, and also i have seen many youtuber also promote it, that prove if this platform really legit and the founder of Bitmex Arthur Hayes has good marketing strategy to increase number of trader. Deposit and withdrawal is safe but margin trading with high leverage is not really safe.
I guess anyone who wants to go into marginal trading should always know what they are in for in the first place before even making the attempt. One thing a lot of people tend not to realize is that marginal trading when it comes to getting liquidated easily is a lot riskier than normal style of trading, but as they always say, the more the risks, the more the potential to profit much.
Nevertheless, bitmex is a good platform that has been thriving over the years as a good leveraging platform, so in terms of safety when it comes to security, as long as the individual make use of the added security features, they should be fine but if it is about safety of not getting liquidated, that is based on each individual's knowledge.