I do not think that there is anyway at least one honest cryptocurrency exchange, and I dont advise anyone to keep funds on the exchanges all the time.
Even any of the 10 exchanges listed by you can be hacked at any time or end up with fraud at a certain moment.
In this point I agree with you
IF you Don't have key you don't have coinIt seems like this "if you are not holding the private key then, the coins does not belong to you". We can't blame people who doubted now with some exchanges, even though they are look likes legit now. Because recently we have crypto exchanges that victims of hacking and exit scam by the owner. I did not say in generalized but that was the point of view now from crypto trader. However, trading is still profitable.