Never heard od crex24, I checked it on coinmarket and it has a really low volume, despite the fact that apparently you can deposit and withdraw fiat easely (you can't do it on many exchanges unfortunally)
Lots of new exchanges appear each month. On the one hand it's good because they are cheap to get on as a coin, on the other hand they don't have much volume.
Many new exchange come lately and idk whether this will give a good or bad impact to cryptos. Tbh, I am afraid to risk my money at the new exchange, I prefer to use the well known one.