Again you are ignoring reality. It is not the name but what it means that is the issue (RCs believe papal infallibility existed before it was formulated as a doctrine).
Rome invented sola ecclesia when she made herself alone the supreme authority on doctrine. Tell me how you alone can claim to be the only entity on earth that can infallibly, authoritatively define both the content and meaning of Scripture, Tradition and history, without claiming to uniquely be the supreme authority?
This would ignore the 25 million or so adherents to the teaching of Oneness Pentecostals.
Irrelevant, as the argument never was that SS will result in universal unity, nor that it results in comprehensive unity, which Catholicism doe not do either, but that it can and has resulted in a widespread strong unity on basic truths and thus a common front against those who deny them, making them a target or both Rome and liberals and cults.
And that Catholicism in its sects and division also must assent to certain truths while allowing differing degrees of dissent relative what magisterial level, a teaching falls under (this itself being a subject of disagreement).
That is the real world, but as by being convinced that an Itinerant Preacher from Galiliee was the Messiah, despite rejection from the magisterium who sat in the seat of Moses, souls are to be convinced and authority established upon Scriptural substantiation in word and in power. (Not that i do not think i much lack in this a compared with Scripture).
Rome invented sola ecclesia when she made herself alone the supreme authority on doctrine.
Christ established His Church and gave it authority guided by the Holy Spirit, the pillar and foundation of truth.
If we disagree on this, which is likely, it is a different topic than whether the doctrine of sola scriptura is unworkable, unscriptural and unhistoric.
That was my argument. That it does not, and cannot, result in unity of dogma and doctrine: one Lord, one Faith, one baptism. As one example, I cited sola scriptura Oneness Pentecostals.
Again, if you are conceding this point, I'm done on it. If not..
thanks for your reply.