The problem here is less about whether supplied jurisdiction exists (it clearly does) and more about whether the Church can exist without any ordinary jurisdiction at all.

You don't know what you're talking about.  You've obviously never spent more than 10 minutes researching this topic.

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Old Code of Canon Law 1917 (i.e. OC)
New Code of Canon Law 1983 (i.e. NC)
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1.  The salvation of souls is the highest law  (NC 1752).  The sacraments are on account of men.
Comment - This is self-explanatory.  The Church exists to provide grace, not create red tape.

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2.  In common error or in probable doubt, the Church supplies jurisdiction (OC 209...NC 144).
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§144. In factual or legal common error and in positive and probable doubt of law or of fact, the Church supplies executive power of governance for both the external and internal forum.
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Comment - There is probable doubt because Quo Primum commands all clerics to use the old rites, while new-rome only allows the old rites if the new rites are accepted.  This condition by new-rome is illegal and sinful, so those priests who continue saying the old rites are protected by law, and have probable jurisdiction to follow such law and avoid sin.

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3.  Danger of death (both temporal and spiritual).  Those in "spiritual danger" can request sacraments/mass from any priest.  (OC 882 and 2252); (NC 976 and 1357)

976 Even though a priest lacks the faculty to hear confessions, he absolves validly and licitly any penitents whatsoever in danger of death from any censures and sins, even if an approved priest is present.

Comment - This is also self-explanatory.  Who defines "danger of death"?  The penitent, because one never knows the hour of death, so if the penitent is in mortal sin, they can request confession as a matter of necessity.

4.  Even censured priests can provide sacraments for "any just cause"  (OC 2261...NC 1335)....(OC 878...NC 967 & 970).
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Can. 1335 If a censure prohibits the celebration of sacraments or sacramentals or the placing of an act of governance, the prohibition is suspended whenever it is necessary to care for the faithful in danger of death. If a latae sententiae censure has not been declared, the prohibition is also suspended whenever a member of the faithful requests a sacrament or sacramental or an act of governance; a person is permitted to request this for any just cause.

(Paraphrasing of multiple codes NC 967 & 970)  Ordinaries and superiors are not to restrict jurisdiction. If the priest is suitable and the good of the faithful requires his services this jurisdiction cannot be refused to him. Clearly traditional priests should in justice receive personal jurisdiction and that everywhere.

There are three cases in which the Church supplies.  1) When it is commonly believed that the cleric possesses jurisdiction/faculties, but doesn't for whatever reason. 2) When there is positive and probable doubt that the priest's faculties apply in a particular circuмstance, but in reality don't.  3) In danger of death.

The purpose of this canon is to allow a priest who knows he has incurred a secret censure to administer the sacraments, without a scruple, if he is approached.  But this canon does not give faculties to a priest who never possessed them in the first place.   A priest who never possessed canonical mission does not receive it by virtue of this canon.