You've missed part of my point. There are plenty of people who buy classic cars with no intention of ever using them, and the same principle is being applied to videogames. The fact that one market is more mature than the other is by and large irrelevent - the classic car market is just a susceptible to a crash in values as any other, and indeed suffered badly at the start of the 90s.
I'd agree the classic car market is safer than the videogame one, but the AES market is considerably smaller than the classic car market is, and if a collector is desperate for a certain piece to add to their collection then they will pay top dollar for it - whether it is a car, an AES cart or a baseball card.
You're the one who brought up the idea of using the stuff/not being able to use the stuff, as if electric cars had something do with it, as if the PS5 makes the Neo useless or something, so I explained that being able to legally run the cars is not an issue. There is no law stopping you. Cars at race tracks don't pass state inspections, they have no airbags, emissions gear, etc. I know families who have been racing the same damned MG chassis since the late 50s (!), they will keep doing it.
Now, cars that don't run on the other hand are still quite appealing. If it won an important race...that's always going to be a true statement, and that race is probably on video making new fans every year. The car may very well be extremely impractical or impossible to actually drive without direct support from the original team that ran it, which may not exist anymore...it doesn't matter. The fat old men who buy them don't fit inside anyway. If I were a billionaire I would have a Lotus 72D for sure, I'd have to pay someone to fit in it probably. When it wins a vintage event, hey, its my car, I won.
Here I'm talking about cars that are truly special, sports prototypes, open wheelers, or more famous touring and rally cars, things that are historically significant or made in super low numbers or were made in large numbers but were too cheap to ever be preserved and then became something as good as rare, like the Honda CR-X for example (once a $12k car, then a $100 car, and now a $25k car, strange how that works...). The millions of later day limited edition Mustangs in garages, convertible Vettes, Chevy SSR, Plymouth Prowler, that shit is for sure useless in the long run. There are simply too many of them sitting around in excellent condition.
I don't think running Neo carts on something is really ever going to be an issue, also as you said most collectards don't want insertion marks, etc so they are just boxes. In that case its hard to imagine it being worth all that much once kids born in the 70s/80s are dead. If you can't/won't play it then its literally just a plastic box with a sticker on it. Its not something with any inherent worth, it has to be learned and who's going to teach that? While I'm absolutely not in the market, there are many classic cars that excite me even if they originally came and went before I was born. Simply being told that a video game used to be good when it ran...I don't know if that's going to keep AES prices up.
The next ten years will be interesting.