Aside from the danger, there is a litany of things you can do in a car that you can’t on a bike.
You can’t carry much luggage. You can’t go much more than 100 miles on a tank. You can’t adjust the air conditioning. An outside temperature shift of just a few degrees can make it too hot or too cold. Fog or rain make it miserable, not to mention even more dangerous. You can't scratch an itch, blow your nose, take off your sunglasses, browse music playlists, talk to a passenger, sip a drink, nibble a snack, dictate a text message to your phone, sing (your visor fogs up), or pull over and tilt your seat back for a power nap.
Road surfaces that car drivers breeze over without a second thought are bristling with hazards to a motorcyclist. Potholes, tar snakes, cracks, grooves, a lip between lanes where one has been repaved and the other has not — all these can wrest control from an unwary rider.