No, they didn't prove anything for 2020.
The only thing the PS3 proved in 2006/2007 was that the PlayStation brand and exclusives and the PS4 advantages (f.e. Blu-ray drive) were strong enough arguments for many people to justify a 50% higher price tag compared to the (at that point even better performing) Xbox 360.
The only thing the Xbox One proved in 2013/2014 was that the Xbox brand and Kinect 2.0 weren't strong enough arguments for many people to justify a 25% higher price tag compared to the (to this day better performing) PS4 with a lot more exclusives.
Movie tickets have more than doubled since 1995. Has the number of sold movie tickets halved since then because "entertainment dollars aren't affected by inflation"? No, they have gone slightly down in the last years, but are still above the 1995 numbers:
Even though there are less and less reasons to go to the cinema with much improved and affordable home cinema/entertainment solutions in the last decade: bigger TV screens, 4K TVs, sound bars, Netflix, 4K streaming, very popular TV shows which are better than most new movies...
The problem is, that we have a very gradual increase in price here, something we didn't have for Video games. Nobody seems to want to exceed the 60$ pricetag for a new game. And the 600$ is considered a similar mark. But the way hardware goes, that one will have to fall some day.
Inflation is also a bad parameter when you have other things that go against it. If you exclude Tetris and Mario, what games even made it past the 1 million mark before the turn of the century? During the 6th and 7th generation, especially with PS2 and Wii, video gaming exploded in numbers, more than offsetting the inflation with sheer sales numbers. Nowadays, A game selling less than 1M is a huge disappointment unless it's an indie title, but 20 years ago, selling over 100k was already a big success.
You also have to consider that publishers at the time released up to 30 games a year to have something for every quarter; now with the microtransactions, DLC, and so on, they got those covered with a stable baseline and release half a dozen a year at best, which also cuts down on development costs. They don't have to raise the prices with their in-game sales, further cementing the notion of fixed pricing in the videogame scene.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454
The Steam/GOG key gifting thread: https://gamrconnect.vgchartz.com/thread/242024/the-steamgog-key-gifting-thread/1/