Ball bearings used for wheel bearings are angular contact ball bearings, they are designed to handle significant side load as well as radial load.
True the "ball bearings" in a shape you think of first are primarily radial.
The original ball type wheel bearinsg were obviously designed or evaluated for the application, and have worked great for 3/4 of a century or better.
Tapered roller bearings are also good.
Lots of modern stuff has gone back to ball type wheel bearings, now they're an assembly of two bearings relatively close together as one unit.
