I am drunk and having a hard time searching this so maybe someone here can dumb this dumb for me.
The big rounds that are 20mms and up... what's the point? If you need armor penetration you can just use rockets? So are they just more accurate for longer distances?
Or are there some 20 or 30mm rounds that have proximity fuses for airburst?

What's the real advantage of this big dakka other than chewing through concrete or other types of cover?