How much more buoyancy do you get when that wave hits the front of
the boat? Not much! There is very little added lift to get the bow up over
the wave. Without the added lift the bow will just submarine through the
wave.

Exactly right but you can open the doors and let the water out :-)
They don't "swamp" and sink.
If you take the wave at an angle they will not submarine much, but blue water
comes over the rail on the second wave.
In the Estero River I get wakes as bad as the waves in the gulf on all but the
worst days.