Yes, everyone uses the same panels. But the electronics are different, and that can be significant for those who care. I just read an article about how the new Sony Master OLEDs do a better HDR color translation. Unfortunately can't locate the article.
Yes that’s true, and trust me, I’m one of those ‘who cares’, but the differences are still minor, and unless done in an A/B environment with 2 fully ISF calibrated displays from 2 different manufacturers, most people will not see the differences. Over the years I’ve attended almost every high end video display shootout in NY, watching a myriad of test patterns and real content. The top displays are often very close in PQ and the scoring reflects that. In the case of OLEDs that’s more true than ever and when you speak to fellow attendees there’s universal agreement on that. As an example, LG does a better job than Sony with peak brightness when displaying HDR, but again, if you don’t see the Sony sitting alongside, fully calibrated, you’d never know. Sony would do a bit better with motion, but this year that gap has all but disappeared.
My point is that yes, there are differences, but they’re still subtle differences. Most wouldn’t notice them unless it was pointed out while sitting alongside another TV and even then it wouldn’t be an ‘in your face’ difference. This is why most of these high end shootouts are generally close in scoring. The differences are subtle and as a result, some see one display as slightly better and others see another as slightly better. I’ve been on the AVS forum since its inception, and you’ll rarely find people in general agreement as to the ‘best’ TV. The last time there was widespread acceptance as to the ‘best’ TV, was back in the Pioneer Kuro plasma days.
Today, these OLEDs are all stunning, regardless of whose name is on the display. In actuality, I find the OS of the display more important than these minor PQ differences. I have a large screen Sony LCD with the Android OS and I find it horrible. It’s laggy, quirky, often freezes and a real PIA. Sony released many software patches to try to fix it, but it’s still bad despite some improvement. It’s detracted from my viewing enjoyment despite the very good PQ. I’m amazed that Sony stuck with Android, since other flavors of Android work well in other devices. The newest Sonys are better, but still not buttery smooth. OTOH, my LG OLED’s OS is quick, snappy, never freezes and never gets in the way of my enjoyment.