I think this erases some interesting nuance. The original Gundam is unabashedly a toy commercial--ostensibly marketing to children in the exact same vein as the OG Transformers--except apparently nobody told the director, so it's an extremely emotionally mature show (more so than nearly all YA fiction) where the main character, a teen soldier, is narrowly escaping death, is killing people, is watching everyone around him be killed, is suffering the effects of PTSD, is being openly used as an expendable tool by his superiors, is on the run for his life being hunted by half the world, is coming to terms with the costs of war and the throngs of innocent bystanders being reduced to burning ash for the sake of cruel and ambitous men, and did you know you can buy his cool robo-flail accessory at Toys 'R Us today?

The original intended audience for Gundam was supposed to be college students if I remember correctly and not highschoolers. 1976 was the real start of when you had this massive wave of engineering finesse in Japan that overtook everything else in the world. It was the time when Japan was forming an obsession with mechanics, with model kits of everything from fully articulated 1:36 scale 50cc scooters to giant 1:20 scale warships that would take up an entire table. Kids couldn't afford these models as they were priced strictly for adults.

Gundam definitely fit into that "engineering fantasies for young professionals" niche, at least until ZZ came around in 1985. Gundam has the root word of "gun" because they were originally these more grounded fantasy weapons instead of man made demi-gods that appeared in shows like UFO Robot Grendizer. They weren't supposed to be superheroes, they were what engineering minded young men thought would be cool to have if they were given an unlimited budget to create bipedal tanks that could do the job of bomber aircraft, navy destroyers, and orbital bombardment satellites all in one. That's why Gundams, especially Zaku units, move slowly, pivot in unnatural ways, and use jets and wheels for locomotion, because they're giant tanks with manipulators that hold guns and not suits of armour. BattleTech also comes from that same origin, although it and Mechwarrior's development went all in on the "tank but with legs" idea instead of slowly losing their identity to the super robot genre.

The melodrama they mixed in as framing to discuss Japan's post-war military pacifism was incidental to creating and populating the backstory for an engineer's dream unlimited budget mobile weapons platform. So they weren't the Marvel equivalent back in 1979, they were more like Japan's answer to some of Robert Heinlein's militaristic concepts in Starship Troopers and The Moon Is A Harsh Mistress, where the concept came first and the story was just an excuse to see that concept in action.

G Gundam and SD Gundam are more like the Marvel movies, in that they strip away most of the issues being discussed and coast on the aesthetic similarities and caricaturized versions of themes from the source material.