where can I be most sure that the exchange will not go bankrupt, be hacked, etc.?
Didn't you learn anything from recent cases of Celsius, Voyager, and all other centralized exchanges like MtGox?
Read this carefully, ALL centralized exchanges can go bankrupt, be hacked and die, and sending coins to them you are officially not owning those coins anymore.
Exchanges are used for trading and exchanging coins, not for holding, so I am not going to recommend any centralized exchanges, but best ones probably have biggest volume.
I would recommend using decentralize exchange
Bisq, so you don't have to ma compromises or to worry about bankruptcy or kyc.