Oh, that’s simple: belt drive turntables are cheap to make.

Even small manufacturers can tool up to make basic new belt drive turntables. You could just about make your own at home, and that’s how many small manufacturers start out.

Direct drive turntable manufacture is quite different, though. It requires considerably more engineering and capital investment. Motors tend to be custom-made and need more than just a capacitor to drive them. There are benefits, of course, but to the average person wanting a cheap turntable, these extra costs don’t make for cheap turntables.