There is no quantum computer that can penetrate any crypto wallet security on its own, it always has something to do with the owners, there are ways people give hackers the access to their own wallets, either through phishing links or malicious websites, some people still store their recovery seeds online till today, through cloud storage or even email accounts, bad practices altogether.

Like I just said, crypto wallet users are the ones giving hackers the power over them, people are greedy, people are slack, and that's how they get their wallets compromised, keep your private keys and recovery seeds offline. Avoid any only storages they gets easily hacked by hackers, anything that uses email login with a password is not a safe place for your recovery seed.

Also avoid free things, when it's too good to be true then it means you are the price, if you have to claim free tokens make sure you have a separate wallet for this, I also believe that a hardware wallet is the safest as it requires the hardware wallet to make transaction anyway, they don't cost a fortune.