I’ve been based at home for 14 years now.

It’s not bullshit. It’s perhaps exaggerated, and many of the “work from a desk in a specific building” people are the ones who can’t mentor them anyway, but there are benefits in

It doesn’t have to be, you can mentor people in a fully remote environment, but it’s far harder for most ok both sides - especially for young people and people on HN that think WFH means you don’t actually have to work.

Why is it harder to mentor people remotely? Just call them, have a chat, share your screens, drink some tea. It's not rocket science, and I have done it many times with colleagues.

One could even have the occasional face to face meeting, at the office, at either party's home, at the lab, the shop floor, at a co-working space, or even just at a cafe or bar.

Do you have any substantial evidence to support your claim, apart from the strong language?

No just strong language.