Earlier quoted context omitted.
Bullshit. I have the skills for an intermediate-level data engineer, but I find it bland and I'd rather work in computer vision. However, offer me enough and I may reconsider, and I don't think I'm alone in this.
You're not alone, but you're just reiterating that it's always possible to fill an opening by running the salary up high enough.
Put it this way, the company isn't going to pay the employee more than the value they provide. That is the ceiling on salary. So until that ceiling is reached it is indeed a case of higher bidder takes all, as your thought experiment demonstrated. But once that ceiling is neared the company will make the decision not to bid higher, thus reducing the demand.
Thus, there is no shortage, just a shortage to work at the lower salary of companies with lower ceilings, because they aren't capable of leveraging the employee's talents sufficiently to draw from fields with related skill sets.