I think it would depend on what type of clothing a bad guy may be wearing.
A T shirt won't even matter to a frangible round.
A heavy leather jacket with a couple of layers underneath might make that frangible a very shallow penetrator.
Wouldn't want to be the test subject but I prefer a round that will penetrate more than what they say a frangible will.
They may be a good idea in a home where there are family members present but I would only load a couple of rounds and then have the heavy stuff coming out next.
On the streets there are so many variables and possibilities that I prefer something that can shoot through a garbage can or something light like that and not turn into a dust cloud.
The Evil Captain Kirk