Besides, you can close down WAW and use the land to expand the city. You also don't have to expand other airports, which are close to cities and cause massive noise pollutions.
Berlin is a corner case of national capital that is in aviation terms in the boonies. Frankfurt Auf Mein and Munich are big hubs because that's where Lufthansa has logistical bases. The 2000km distance doesn't do anything, that's a short hop for airliners. That means that Berlin will do profitable important routes direct... which happen to be mostly to airline hubs, with few exceptions.
So there's no reason for people from neighbouring countries to use it, it require artificially breaking other airports in Poland to have even a sliver of reason (easily debunked by anyone with idea of state of polish airports). It's whole existence happened because one man had an unresearched biased idea and the party jumps at his whim.
I reckon you're an avid supporter of PiS?
I do not support any party
The connection graph of airlines is based both on where people are, and what logistical bases they can get, and a) LOT doesn't have long range network capable of driving more traffic than Okęcie can sustain b) no other long-range airline is going to operate long range flights from CPK