I think the seal works on two sides.
Preventing too much mud/water to arrive to the bearings.
And a guess, they prevent water ingress at the shaft too.
I find wet mud inside my PF30 one, that kills my bearings from the inside
The only option I found is to drill a hole at the very bottom of the BB, when the bike is horizontal.
I had the same issue with a BBInfinite, and against their advice I drilled it at 2.5mm
If water enters, it has a way out other than trough the back of the bearings.
And my bearings last much longer.
Then BB infinite came with these kind of seals.
Probably better to have a trap, or a purge hole already below the frame to do this.
However I did it on my 041 that didn't have any.