That is weird then. I can't remember the last disc I bought without DV support. Either way, I'm not saying the Sony is better, but you get what you pay for with the Panasonic for sure. Though it isn't immune from issues with freezing etc on certain titles. I've experienced it myself on my Sony with 100GB discs, but rubbing them before playing solved it, although the layer changes are noticeable so it definitely handles those discs less well than the Panny.I ran a Sony player for a while and it was actually incredibly annoying having to manually switch between Dolby Vision and HDR10 since it's not always obvious which disc has it or not and just the act of switching itself is a hassle. From what I've seen it's not even close to "most", it's 60/40 at best with the hundred or so discs I own. The Sony player also has far more issues with freezing and other playback issues. The only problem I've had with the Panasonic is Criterion discs because they arrived scratched half the time.
Edit - it is worth noting that some discs don't list DV support on the packaging but still feature it, at least on UK releases here.