The OP uses the terms “improve themselves” and “better themselves.”
That seems a tremendous understatement. Perhaps I am misinterpreting the OP. Perhaps the poster is not from the U.S.A. and is using the terms in a different sense than I am used to.
“Improve themsevles” and “bettert themselves”–that’s not it at all. There are many people who are better people than I am. Being a Christian Catholic doesn’t make me “improved” or “better” than others.
We want people to come to Catholicism because we believe it is the Church that Jesus Himself established. The Catholic Church contains the fullness of the Gospel. Protestants want “Jesus” in all of His fulness. A popular Protestant hymn is “Turn Your Eyes Upon Jesus, look full in His wonderful Face.” That’s what we do constantly in the Catholic Church. We know Jesus in all His fullness. We want everyone in the world to know Him, too.
I don’t think we have any right, though, to say that we are “improved” or “better” than another group of people because we know Jesus. We can say that He is giving us graces daily that are helping us to become more like Him, without sin. So can Protestants (the Catechism says that they possess a portion of grace). We can say that we hope to enter heaven, but so can Protestants.
We are no better than anyone else on this earth. The lowliest person (in human eyes) on this earth is of equal worth to the Pope himself.
Becoming Catholic doesn’t improve us or make us better. It simply gives us Jesus.
I hope I’m expressing this adequately.