Are non-Christians often saved, even if they never convert to Christianity? Yes. The mercy and grace of God brings then into the state of grace and keeps them in it, if they love their neighbor. However, not all are saved.
It is the heresy of Feeneyism to claim that formal baptism is the only path to salvation since the time of Christ. Then, in my opinion, it is mitigated Feeneyism, and at least proximate to heresy, to claim that salvation outside of baptism is rare or might be non-existent.
I’m considering writing a series of articles on the subject of salvation theology, and the errors on that topic among some papal critics. Having abandoned the Magisterium by making themselves judges over Popes and Councils, they next set up their own doctrines on each subject, feeling no obligation to believe anything the Church teaches. They commit the sin of schism by rejecting magisterial authority, and next comes the error of heresy. Schism leads to heresy.
The three forms of baptism are a reflection of the Trinity, so I cannot imagine that any one or two forms would be rare or non-existent. Also, the only means of salvation prior to Christ were the non-formal types of baptism, and it is dogma that some were saved in that time (to await Christ in the limbo of the Fathers). So it would be contrary to Mercy and even Justice for God to take away this path of salvation, and the Church does teach that it is still available. The question is, would God narrow those paths of non-formal baptism (desire, blood) when Christ arrives? No, for Christ came to bring us mercy from God in person and in the flesh. The path to salvation becomes easier for everyone after Christ, not more difficult.
** I do want to add that there are many faithful traditionalist or conservative Catholics, who have conservative traditional views, but also follow whatever the Magisterium teaches. They do not reject Pope Francis, though they reserve the usual right of all the faithful to occasionally dissent licitly from some non-infallible teachings. I’m very disturbed by the pride and sinfulness of the papal accusers, but do not think for a moment that I would condemn all conservatives or traditionalists.**