From a practical standpoint, it is "locking in" most of those infants to membership in that particular sect. Also, it is making the family a part of a community. However, I don't believe it is advancing any greater understanding.
Believer's Baptism takes on a deeper meaning for the individual because they are at an age where thought was involved. A baby has no idea what's going on.
Not really. Most of the paedeobaptists accept a baptism from another denomination.
In its early days, the PCA even had a study commission examine whether a Roman Catholic baptism would be valid for membership.