I think we generally see eye-to-eye on this.
But this thing here...
Literally everyone. If you consume western media, you likely know what a Spider-Man or Wolverine is even if you don't read the comics or particularly care about the movies. If you play the video games, you're likely familiar with a lot of the older costumes even if you've never picked up a comic. Including a bunch of those is something Marvel game makers love to do.
Knowing about a thing, and consuming those things are entirely different actions. Let me elaborate a bit - *I* can see where you're coming from based on certain assumptions I make about you: 1) you're an RPG Forum talking about RPGS 2) you're *actually* talking about Marvel Superheroes 3) You're indicating that you have interests in these characters beyond either of these two endeavors (comics and TTRPGs).
My gut reaction is SURE - they're "popular" to the NPC normies. But... the reality my head tells me is this: They NPC Normies only know what they're told. They're not wide-spread consumers of these things. TTRPG's are their own distinct tribe of many intense little tribes. Videogame players are their own distinct tribe composed of many intense smaller tribes. Pop-culture consumers - movies, TV are in an entirely different orbit.
The degree of what you an I might agree is "popular" is relative. I own north of 30k comics (probably closer to 40k) going deep into the Silver Age and several complete runs of books up to One More Day where I pretty much quit collecting monthlies... and dwindled down to indies (Basically anything from Matt Wagner, Mobius, and a couple of others). I'll stand and bang talking comics with *anyone*. I've been running MSH (FASERIP) pretty much since it dropped at my table - so barring other campaigns, it's been a constant for the last 35+ years.
So I'm saying this to illustrate that I am a "fan". But the things I'm a fan of - pick your character from the Marvel Universe, is probably for reasons utterly so unknown, so obscure it may as well not even exist for the average modern fan that knows Marvel from all other pop-culture sources OTHER than comics. That includes TTRPG's.
I understand very clearly that these tribes consume comic-media in very different and discrete ways. So Captain America is popular to most people today because by the numbers people have watched the MCU. THAT is Captain America to them.
Captain America, disaffected by 1970's politics, wearing a Disco-pop-collared blue-plunging neckline to his dick-root Nomad-era cap, sans-Star Spangled Shield, but now tossing these weird little yellow frisbee-pucks would cause most modern "fans" to go "W.T.F.?". Or his now current modern Captain America - who now apparently is wrestling with his own realization according to modern writers, he's a Nazi creation that deep down hates America. MOST MCU viewers, the largest "fandom" that currently exists - would also scratch their heads at trying to square that circle too.
So yeah *I* am the outlier here. Not the NPC's. This is part of the problem. The only demographic that making this game makes *any* sense to is precisely no one but ultra-casual, borderline board-game enthusiasts that also happen to dabble in TTRPGS.
Hardcore TTRPG players tend to *not* player Supers RPGS - because it's hard enough to get GM's to run D&D, much less have a GM that wants to run a Supers RPG in lieu of D&D and find players that are willing to play. It's more of a GM issue than a player issue (to be sure).
MCU fans generally aren't going to become such fans that they suddenly want to play a Marvel RPG*
*Now - kids that learn about Marvel via the MCU might do this. And this is important, and where the Dead on Arrival prediction hurts most: Because Marvel can't even run their own Comicbook business anywhere but straight into the ground, what in the fucking world gives anyone the faith that they're magically going to become successful as an RPG enterprise? Those kids that play will suddenly find themselves with a mediocre game at best that will get dropped once the bean-counters realize that the money made on this project will amount to shit. Most of those people coming in via that vector will fade out... and if we're lucky, may decide to have a good enough experience to try another RPG and go a little further. But how many people will this be?
How much marketing do you actually think Marvel is going to put behind it?
Better still - they might discover there are scads of Superhero RPG's already out there with pretty vibrant communities that won't budge on their tried and true systems of choice, because those communities support their own games with their own content that *vastly* covers Marvel, DC, and pretty much every other pop-culture icon out there. Fuck man, I just wrapped up my latest MSH story-arc where the PC's fought alongside Raydeen from the Shogun Warriors against Ghidorah - and Beta Ray Bill, with members of Overwatch, and characters from Mutants and Masterminds off the coast of LA. There's *that* much stuff out there.
I'm saying this game will be mediocre *AT BEST* and that's me being ULTRA GENEROUS, it will have very little support. And any initial sales it makes will plummet with intense speed because Marvel is an incompetent company in their own medium. They deserve zero benefit of the doubt entering into this medium, especially considering their current political manifesto that will demand catering to - not necessarily by us, but by the usual suspects currently ruining pop-culture (and the rest of culture writ-large).