My anecdotal experience may not apply to you, therefore I keep my reply in general.
Few psi pressure in tire makes big difference, too. 20x4" tires don't need much tire pressure to become slick & slippery.
I find Maxxis Hookworm type tires to be very nice for pavement; dense, fine knobs that offer low rolling resistance and better grip than slick tires with grooves.
I notice a trend of fat tire (20" x 4") ebikes using motorcycle tires, I think that robs top speed & battery range, not something I'm going to try.