I mean, I agree, but to be fair I had a positive experience once by letting my employer know when I had already started interviewing elsewhere (really just giving them a heads up that I was planning on leaving within the next 6 months) and to my surprise they were more than happy to match the salary and make changes (for example going fully remote) to accomodate me. I'm still there nearly 3 years later.

Really depends on the employer and on how much they want to keep you and how willing you are to stay there.