You obviously haven't thought this through.  Choked traffic can be its own solution. People might think twice and building in, or moving to, an area with really bad traffic. And it's not as though we're in desperate need for more people and more sprawl.

Constantly adding lanes to accommodate more people is insane.

Spending billions only to wind up with the same problem is dumb.  And that's what happens when traffic lanes are added.

Smarter solutions involve things like congestion pricing.