A good software wallet can be enough for one person who will never get hacked in their lifetime.
On the other hand, a paper wallet can be completely unsafe in the hands of a person who created it using a fake service, bad RNG, or made mistakes with the seed/private keys.
It is possible that an experienced person can use an online wallet and never got hacked, but that is not enough for security reasons, anyone may later fall victim of hack and the use of an online wallet for high amount of money can result to feeling of insecurity and probably the wallet may later even be hacked, hackers should not be underestimated. The probability of getting hacked while using online wallet can be negligible for experienced users but that does not mean the wallet hack is not possible.
The safest are cold storage and hardware wallets, but users should safe their seed phrase safely because offline attack is also possible. But users that do not know about phishing attack can be hacked by entering their seed phrase on a site or through other phishing attempt means. Even haxk on a cold storage or hardware wallet can be possible through clipboard malware.