Two points:
If the Court gets a constitutional question wrong and then defers to that error indefinitely because of reliance, it has effectively transferred the Article V amendment power to the judiciary without going through the state ratification process.
What you call "run headlong into more than a century of that being accepted" I call relying wrongly on dicta from Wong's paragraph 93, which has no force of law, when paragraph 118 is the controlling ruling. We can't allow the Constitution to be de facto amended by simply ignoring law for a sufficient amount of time and then calling it "settled."
The governed never consented to this expansive interpretation of birthright citizenship, as there are no statutes via legislation or Supreme Court rulings that have stated this, or constitutional amendments that proposed this. Those are the normal means of consent of the governed. The tools of government that the people consented to via ratification of the Constitution were not the means where birthright citizenship for all and natural born citizen for all was determined.
Those interpretations evolved extraconstitutionally through the accretion process described in Janus: each successive actor pointing to the prior actor's behavior as authority, until the chain of reliance became long enough to be called "settled law" whether by the Court treating its own dicta as law, or by political actors treating those rulings as broader than they were.
The governed did not ratify universal birthright citizenship. They did not ratify natural born citizenship for the children of temporary visa holders or illegal entrants. Those outcomes were imposed on them, not chosen by them.
-PJ
I think that is a reasonable interpretation. I also don't think that if it is "close", the Court should take the issue forever out of the hands of Congress by making it a Constitutional right. And I think the fact that the class of "Illegal aliens" didn't even exist at the time the 14th was adopted alone makes it "close".
The argument I don't buy is the whole "loyalty" argument, which essentially would exclude the children of anyone who is the citizen/subject of another country, whether they are here legally or not.
Just a note that there is no such phrase in Janus.