If one classes critical biblical scholarship as “scientific”, one needs to recognise that, like other science, it has faith commitments underlying its paradigms. Kuhn and others have shown that abundantly. It hasn’t had a reputation, either, for humility over the last century and a half (“assured results” and all that).
One such faith commitment is to a Victorian theory of the evolution of religion, which has never been attested externally as archaeology etc have advanced - for example, the “impossibility” of monotheism in early Israel was overturned by its existence in Egypt under Akhenaten before the Exodus. But that old theory has largely moulded the internal dissection of the OT into the purely hypothetical sources you mention, with the historical reconstruction of both Israel’s religious history and the writing of Scripture sitting on top of that train of externally unverified assumptions. The consensus on sources has been lost - for example a significant strand now places “E” before “J”, so where does that leave the priestly redactors?
Cutting through all that is the teaching on inspiration from the NT writers like Paul, Peter and writer to the Hebrews on Scripture’s inspiration by the Spirit of Jesus - and of course the teaching of Jesus himself in words like “Scripture cannot be broken”. In these founders of our Christianity, one can trace a broad concept of inspiration that encompasses not only the “original” prophetic voices but their circumstances, the circumstances of their scribes and editors, and indeed the whole circumstances of Israel’s history. The net result is that the final locus for the transmission of “the very words of God” (so Paul) is the Scriptures as we have them.
At that point, it seems to me, one faces something of a choice: is ones attitude to Scriptural authority Christological and Apostolic, or are those considerations to be relativised by a continually changing modern scholarship? That’s not to downplay the vital importance of scholarship, but to insist that the faith commitments behind ones paradigms are fully recognised - and prioritised.
Sola Scriptura is often misunderstood. None of the Reformers were “Fundamentalists” in the sense of slam-dunk literalism - even William Tyndale’s understanding of “the literal meaning” was avowedly genre-sensitive. Scripture was finally authoritative, yes - but the Church Fathers as “primitive” authorities were still valued (see the quotes in Calvin), as was Church tradition (eg Creeds), Ecumenical Councils, reason and scientific discoveries too (Calvin again on the relative sizes of Jupiter and the Moon). All these could be guided by God’s Spirit and were taken seriously. But all of them were recognised to be human and fallible - actually a humble position as it meant one was always open to fuller understanding of ones prime material, and should never hold one’s interpretation to be infallible (or even “assured”).
Once Scripture is downgraded from the basic paradigm “men spoke from God”, then inevitably one or more of these human tools will be elevated as judge over it. In our age, of course, the commonest such judge is “science”, whose “Sola Scientia” myth is deeply embedded in our culture.