I think you have summed up perfectly the attraction of Protestantism.
I have never known an instance where an ex-Catholic who becomes Protestant, whether Evangelical fundamentalist, or Anglo-Catholic Episcopalian, didnāt suddenly transform into an expert on Church doctrine.
It may also explain why even cradle Protestants are so SURE of Church doctrine, whether it be their own or another Church.
Catholicism is not like this. It CAN be boiled down into simple basics of course, but that doesnāt explain the Liturgy and the Sacraments, much less Apostolic Succession, the ministerial Priesthood and many other issues and concerns. Catholicism will always CHALLENGE the believer in his entirety, both in Faith and in Intellect, just as it surely did in St. Paulās time.
IOW, Protestantism allows one to inhabit a kind of Christian comfort zone. One knows exactly where one stands, exactly what one believes and exactly what others believe.
Some may object that the same might be said of Catholics, which is true, but NOT of Catholicism. Unlike Protestantism, Catholicism does NOT make other religions a source of negative inspiration, as does Protestantism with Catholicism. That will always be fundamental to Protestantism. Without Catholicism, there would be no Protestantism, just Christian anarchy.

Protestants depend on Catholicism to hold them together, whether they acknowledge it or not. If Catholicism were to suddenly die out, who would fill the void? Lutherans? Presbyterians? Anglicans? Baptists? Fundamentalist Evangelicals? Jehovah Witnesses? Unitarians? Mormons? Who? Nobody of course. But without Catholicism who would inspire āCatholicā Lutherans? āCatholicā Anglicans? and all of the other Protestant denominations who are taking a renewed interest in Catholic Liturgy and Sacraments?
Thank God, we never have to come to that depressing outcome, since both Catholics and Protestants know that the Catholic Church is protected and will triumph in the end. But until then, Protestants may enjoy their chosen denominations.