Earlier quoted context omitted.
Huh, for what hide that? Would they proactively fire you? Here, it is always joked that intentionally giving those signals is the trick to support getting the desired pay raise.. some years ago even saw one guy pulling that off.
The trouble is if you're just idly searching a bit and aren't in a hurry, you might not want your current employer (or co-workers) to start planning to be rid of you soon. At the very least, it might make things awkward.
When coworkers would learn I'm searching for something else they either understand me and/or try to persuade me not to jump ship. Why should they, lol? And if I go they wish me all the best as I would do to them.
And actually just the same for bosses?