There is a lot of discussion and debate about whether that is true or not. I find it all fascinating.

Bike tires having a round profile vs a flat car tire, bike speeds vs car speeds, etc.

My analysis of the subject of tire grip is that the hard and sharp little nibs on the asphalt bite into the soft rubber of the contact patch. The road bites the tire, the tire does NOT bite the road, it conforms to being bitten. Therefore, the more rubber available for the road to bite into, the better the bike's cornering grip. Tread is the absence of rubber. In my experience this holds true whether the road (teeth) is wet or dry.

Standing water (puddles) and painted road lines are a different story. There are no teeth available and all bets are off, treaded or slick. Avoid leaning and braking or on your head you will go.

Knobbies for off road function in the opposite fashion. The knobs are the teeth that dig down into the soft surface and bite it, the soft surface reshapes itself and complies to being bitten to provide vehicle grip.

That's why knobbies SUCK at cornering on asphalt and slicks will put you on your ass on sand, dirt, mud or grass. I have the scars to prove that both are true.