I was in this situation many times. You'll see the reality of it the day you leave: in a few days, maybe a month, you'll be forgotten there.

When I leave, that corporation is no longer my problem :)

This also has happened to me multiple times.

And to the comments saying the employer could "replace you any time" - most cases, they just don't know how to do so, or have the time and money to do so.

This strange article teaches you to do your employer's job by making it easier to replace you.

Agree, that's why I think the article was written by a manager that lost some key people and he is in big trouble.

Meaning your employer now has all the more reason to replace you as soon as an opportunity presents itself

They can. But it would be very expensive to replace more than 20 years of domain experience.

It would probably be a lot more expensive to replace more than 20 years of domain experience immediately because you quit to go work at rand($FAANG).

Exactly this. If you are a single point of failure knowledge silo, the business sees you as a liability since if you decide to quit, their business is then screwed. This is why turning yourself into a silo is making yourself disposable - it gives the employer a very good reason to try and find an alternative to continuing their reliance on you.

I agree, meanwhile they prefer giving me a raise than start looking for backup or replacement

Why does one exclude the other?

short term, it cost more to bring a backup/replacement than give me a raise.