In my experience, Mini B was mostly used for data transfer, along with some other port to do the charging. Micro B got introduced as the "all in one" data+charging port. I've seen both kinds of ports break, but only the Mini B ones that were also used for charging; the data-only ones, were fine.

My conclusion is that charging ports use more insertion cycles and are more likely to break, and I keep magnetic charging adapters in all of them (as a side effect, twisting the cable or pulling at an angle just disconnects it, instead of breaking the port).