Fortunately for me I didn’t send any big amount to the wallet and I’m very sorry for your loss, it’s so annoying and upsetting to lose in a such way you don’t have any chance to recover your assets. After looking everywhere for the exact reason my wallet keys were stolen I think before I stopped using it on my computer I downloaded a program called tool kit windows to activate office package. It’s not a certain thing but somehow the hack happened on my PC as it’s impossible to happen on a mobile device that I use only for surfing.
I read that article you shared and even Metamask shared a similar article on how to beat these sweepers for people that have assets and tokens other than the main coins BTC,BNB,ETH….., for me I don’t have any tokens in my wallet so I don’t need to do these steps which are possible for people that want to withdraw their tokens but the sweeper eats instantly the gas fees they need to use for withdrawal.
Best thing to do is to avoid opening any wallet on a computer device that is attached to internet that much and used for things. As you said you will be always an easy fish for hackers.