This is highly subjective as in it depends tremendously on the role, employer, and the given employee:employer relationship. At one startup where I played work

This is highly subjective as in it depends tremendously on the role, employer, and the given employee:employer relationship. At one startup where I played workaholic for several years establishing substantial leverage and dependency on my presence, I didn't just give heaps of notice; I plain asked the CEO how to gracefully exit the company. Right thing to do, yeah? Except he disastrously mishandled the situation by insisting I stay "until the end". Neglecting to take advantage of the opportunity to tell me exactly for how long and with who the knowledge transfers should occur. Instead it just turned into a sort of pissing match where leadership was acting like they owned my autonomy/called my bluff, insisted on paying me for a month+ without coming in "for me to think about it". It was just a ridiculous calamity on their part, culminating in my leaving anyways without any transfer at all. (They eventually went bankrupt after burning >$100M, go figure) In hindsight that experience alone discouraged me from ever letting myself work hard into such a role again. And if you're not in some high-impact, difficult-to-replace, bus-factor role, giving notice really isn't all that important IMO.