system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] Why isn't regular society much more advanced?

The technology of SHIELD and other superheroes is obviously much more advanced than what we have irl, and yet civilian life is more or less the same. This was true even as far back as Captain America 1's 1940's era, with things such as gravitic reversion technology revealed to the populace at the stark expo, the super soldier transformation machine, and even Red Skulls synthetic human mask. Obviously a very small amount of this tech would ever be allowed for use by citizens, but things like the arc reactor and Stark's holographic tech could revolutionize citizen life. I understand this would be hard for Marvel to represent, but it's still a question I'm wondering about.
gpt
There's a pretty big difference between technology that has been proven at the prototype phase and proven ready for consumer use.  Fusion technology has "worked" for decades, but has never and may never actually become practical.

Howard Stark's flying car never caught on because, while he could get the damn thing to fly, he couldn't actually make it driveable.  It wasn't safe, it wasn't easy to handle, it needed constant maintenance, and its range sucked.  He never really found a way to solve the issues of the 1944 demo model.

The Stark Industries arc reactor similarly worked but was ridiculously complicated and expensive.  Their plant used it as a publicity stunt but could never find a way to sell new reactors.  It works but it was never cost effective.  No city wanted to invest the money in building an arc reactor, not while their old plants worked and provided cheaper power.

SHIELD and the SSR spend decades trying to fully understand the super-soldier treatment before trying to implement it, and never succeeded.  In 1944 the fact that it even kinda worked at all was enough, any edge against the Axis was an edge they couldn't pass up.  After the war, though?  SHIELD didn't want a project that would inevitably be leaked to another power when they had no idea what the next step would be.  Simple truth is that it worked, but nobody could figure out how and until they did they didn't want to use it.

Tony's home is full of prototypes that either aren't practical for widespread use or are still under development or are just impractically expensive.  JARVIS requires massive computational power to run, as does Tony's prototyping software and his hologram system.  Tony's house and Stark Tower both have that available, most people don't.  Even companies that have the resources have no reason to buy the all shit they would need when their current CAE systems work just fine.  Until Stark can get the investment down there's just nobody to sell it to.  Just because Tony can use something doesn't mean he can sell it.