Nothing needs to be feared in crypto, because everything we do must have risks. Because the possibility that happens a little if we save coins in the wallet online and at one time the site will disappear, actually I am not afraid because there is no way that could happen.
Who told you the possibility is little. please try and research before you make ill-informed information. Online wallet do not backup your private key. If you store your coin in an online wallet and the site disappear that is the end of everything you hold because you can not recover your coin again and that is the major reason why we always advice crypto trader not to put huge amount of their coin in an online wallet. Even recently, one of the top executive of binance make reference to this that its not advisable to keep huge crypto in an online trading platform. many people put their coin on coinbase becuase they believe if coinbase goes offline, they can legally track them down. if you put your coin in an online wallet that are new and have not gather more credibility, you are on your own.