It's ultimately simple: many people, especially people from professional–managerial class (PMC) which keeps rising in its aggregate wealth & prominence during the recent past, will tell you (maybe in a comment section on HN or some other media) that using "counter-offers" as a career strategy is unethical, akin to blackmail. This is a (often performative) niceness narrative common to the social plane.

Be aware that it very well could be the same PMC people who consistently use various tricks to lowball (google it) offers for productive people like you and me in their day to day hiring practice, simply because they can - this is the logic of harsh business plane.

There is no contradiction here.

Counter-offer is something you can use as well.