I would consider that advice by a fake expert. Whoever has time to suggest things that they themselves are not doing, they are a fraud who does not believe in the things that they are preaching.

No, that is not how things work. There are automated tools by now which will scan your machine for every possible known wallet type, desktop and extension wallets. Even if they are all password protected, which I assure you in many cases they are not, where are these passwords most often stored? On the computer in plaintext, or on the computer inside a password manager. If you have complete access to somebody's system, you can do anything. If you don't know how, it is mostly due to a lack of your own imagination. Sometimes people compromise systems and wait months or even years, gathering information, before executing an attack.