Well, it's not such an either or....there have been plenty of modern-day "prophets" who have made claims as Smith had. Some more believable than others, but all united in their contention that the Catholic Church went off the rails somewhere along the way.
And in so doing, note that they always put themselves above the authority of the Church...you can't judge the Church to be heretical, unless you yourself know what is heretical. But we maintain that you can't actually know what is heretical without the Church.
“you can’t judge the Church to be heretical, unless you yourself know what is heretical. But we maintain that you can’t actually know what is heretical without the Church.”
God the Father and Jesus Christ personally appeared to Joseph Smith and informed him that all the churches at that time had gone astray and called on him to restore the fullness of the gospel.
Do you really think someone should reject what Christ personally said to them if the Catholic Church disagrees? That would put the Catholic Church above Christ! Even if you don’t believe in that specific incident, you should at least be able to see in that how someone does not need the Catholic Church to know heresy from truth. If you don’t, you deny the reality of revelation and power of God.