I agree that buying a ledger or a trezor would be the best way to keep your coins safe, we are talking about the cutting edge technology that would be the highest end of security, if you think that could be hacked that means everything else could be hacked as well. However I have been using blockchain.com for years now (blockchain.info if you remember it) and I could tell you that they are as legit as it gets as well, I haven't had any troubles with them for the past 8 years and I do not think I will start now.

Not saying they are the safest but they are safe enough that unless you have huge amount of money there to worth the hack, people will not really try to hack you since it is too hard and if you want to achieve something so hard as hacking it, you would want a lot of money, not couple thousand dollars.