Neil Diamond has an excellent one.

But what if you wanted plastic surgery to look like a quasi-human and needed help paying for it?

Seinfeld “The Chinese Restaurant” S02E11

Once physical access is achieved you have already lost. They can just brute force your brain. A safe is perfectly fine for the usual remote attacker.

There is always the possibility of the end of humanity.

KDE Wallet is primarily a password manager. So if the launcher saves your password this is probably where it is storing it. Why invent your own storage when you can use one that is already built? For more information I recommend the ArchWiki which has plenty of information that is not arch specific. Also if you use Gnome I would imagine it would access Gnome keyring which serves the same function. KDE Wallet