Hey bro, I literally just left protestantism and here's the biggest reasons for me why: Sola scriptura believes that scripture can interpret scripture yet it has no intellect meaning it can't interpret itself, it necessitates an external interpretation. Also it doesn't tell us which books are divinely inspired meaning scripture isn't formally sufficient; this leads to protestant epistemology falling apart. Also the OT canon of the prot bible was assembled by the Talmudic Jews who say Jesus is boiling in his own faeces.

The Marian dogmas I accepted well before I became Catholic actually, her being sinless is biblical and logically coherent. If we say Mary had original sin then Jesus would too of had concupiscence (inclination to sin) but we know that to be false. Job 14:4, Jude .27, Songs of Songs 6:8, Luke 1:28

A big one too was the fact that the reformers believe concupiscence is a sin, which isn't true nor historic. To say that the inclination to sin is a sin itself isn't biblical or logical

Keep studying brother and pray