Confused about Groundsheets - need advice...

I hear a lot about breathable ground sheets

Just bought a caravan that has a breathable groundsheet for the awning  - looks full of holes to me! surely I would get my socks wet in the morning? 

but I was also given a carpet to go on top of the groundsheet - surely tat would negate the "breathable" in  Breathable groundsheet?

 Also saw in Aldi last week some sponge florring that locked together to form a floor inside an awning - looked a good idea - nearly bought some - is it a good idea?    - think the ones with holes may get your socks we again?

Whats the situation everybody - not been out at all with the new van yet ......... shall I just take waterproof socks?

pete