The security of the user and their funds is usually up to the user than the website. Basically its possible that a bitcoin service or exchange can get hacked and the customers will lose all their funds, however those chances are slim compared to someone reusing the same password or not using 2FA.
We have all been new to Crypto and saw how easy it is to get a virus or get your email hacked and your funds stolen. So its important that each user take precaution and use a unique password for each site and always use 2FA. And never use SMS 2FA seems the sim swap hacks are very common.
But in general you should never keep all your crypto on anything online whether an exchange, online wallet or gambling site. Get a perfect cold storage setup and know your BTC will be safe forever.