Greenmonsters
Wannabe Duck Boat Owner
I do see younger players up to 16U occasionally using a 1B mitt. They are padded and braced differently and will affect receiving pitches. I do see catchers dropping balls for a variety of reasons. Sometimes the glove is too stiff and hard to close. One catcher I worked with had problems closing her glove. Upon looking at her glove and how it fitted, we determined her wrist band was cinched too tight and prevented her from closing her glove. We had her un-cinch her wrist band and squeeze the glove closed before cinching her wrist band... Problem solved. Another catcher could not keep the ball in her glove unless it hit the pocket dead on. Closer inspection revealed that the stiffeners in her glove had broken and the glove would simply fold over on anything out of the pocket.
It does depend on the catcher's level of interest, if they are playing rec ball or are a casual player, the 1B mitt is fine. If your catcher is more serious and plays the position regularly, take the time to get them a good fitting catcher's mitt.
What ^^^^^^ said. Catcher's mitts are made for the same reason that master carpenters don't put in screws with a hammer