Yes, and most are radials. And you really shouldn't put a lower profile tire on a bike designed for a higher profile tire.
That is true. But what I was trying to say was, that when referring to "newer tires with higher pressures", the "newer" could refer to those with lower aspect ratio vs those with higher aspect ratio. A /50 tire (radial) has not been around for THAT long and it usually runs with a higher pressure than a /70 (radial)