The main idea of this opening is to get a mass of center pawns, for less development. How can White get his pieces out before Black can develop too many pieces?
The line that you refer to is probably 1.b4 e5 2.Bb2 Bxb4 3. Bxe5 Nf6.. I recall some early opening books saying that this was a bad defence because it surrendered a center pawn. The more modern view is that Black does get a very fast development in this line which is quite dangerous. I gave up the Polish when this started to become well-known. Until then I had good results. Often I got something like a reversed Sicilian with a very useful move thrown in.
I have not kept up with recent developments but there is an article in New in Chess yearbook 132(2019) which is where I would go to catch up.