There are lots of custodians with different storage models. If you have account at some reputable service, good password and 2FA set up (non-mobile) then I think accidents are always super ultra-rare or basically nonexistant. Of course you also have to just HODL and for example not send your crypto to some scammer (that ofc isn't a problem that a custodian will solve anyway).
Have to note that when there are millions or maybe hundred of millions of people with crypto wallets, there will be also some amount of "false positives" reporting lost BTC, for example people who have sent their BTC to wrong address drunk or high, and then afterwards think that its the platforms fault.
Have to note that when there are millions or maybe hundred of millions of people with crypto wallets, there will be also some amount of "false positives" reporting lost BTC, for example people who have sent their BTC to wrong address drunk or high, and then afterwards think that its the platforms fault.