Why don’t countries do this already? E.g., most European countries and presumably the US dislike that Ireland undercuts corp tax, so why don’t they penalize corporations who operate in their borders but are headquartered in a country that doesn’t have agreeable tax laws?

Well they sometimes do (e.g. fine them) but at a scale where it matters these are companies that also have leverage - if Amazon responded 'Ehhh we might stop delivering to the UK then, Brexit is already an expense, with this too ...' and then the Government is the government that lost/banned/there-is-no-good-spin Amazon.

Within the EU, (or EEA perhaps) I vaguely recall there's some restriction against penalising for things like this, as long as the other nation is also a member state. (Since viewed as a whole, 'one EU', it should be fine, I suppose.) Struggling for the right words ro search though.