That's the Catholic position regarding the place of Scripture as a source of revelation.
That's the Protestant position regarding anything having to do with the House of YHWH. If you say something to a Protestant about the things of YHWH, it better be defensible in the Word, and not by way of a verse here and a verse there, twisted to fit the thought...
But that still leaves plenty of room for Protestant tradition (subservient to the Bible). Just go to a library or bookstore and look at the formidable works written by Protestant hands (using 'protestant' in the broad sense). But one way or another, your use of ONLY is not valid. That is solo-scriptura.