So to me, an understated aspect of Watchmen is that it deconstructs supervillainy. Without the need for a rotating rogues gallery in the name of endless serialization, wannabe supervillains end up dead, imprisoned, sticking to common profitable crimes, or going straight like Moloch. I think this a missing aspect of other attempts to deconstruct the genre like Marshall Law or the Boys, because if there isn't a threat on the level of the Legion of Doom or Darkseid, then superheroes are just a solution in search of a problem, and if there are supervillains, then the superheroes need to get their shit together. This was also a problem with the League of Extraordinary Gentleman, were told about much of a threat superheroes are, but all they do is lounge around to be marketed, while the League goes out and tackles issues that a superhero could actually help with, such as the aliens from War of the Worlds, actual authoritarians like Big Brother, or even the antichrist.
Hard agree with at least the parts pertaining to Watchmen. Moloch's quivering little "Oh God, I spent the 70s in jail." is such an effective refutation of such a huge number of tropes at once, and hits above its weight in contributing to the sense that Watchmen proper is set well after the party has wound down, so to speak. I really wish that it had made it into any of the adaptations.
My endorsement as this pertains to Marshall Law and The Boys is much more tentative. Marshall Law is simply on my to-read list. The Boys is almost entirely about the idea that superheroes are just a solution in search of a problem, but also doesn't commit to an actual in-universe angle on what supervillains are, or whether they exist at all, in a way that severely limits it's ability to say anything about anything at all; they go from a real issue to which superheroes are framed as a bad solution, to controlled opposition stage-managed by Vought, and it's not a clean transition; as a comic it's concerned with getting in a lot of (decently funny) shots at the meta-editorial level at the expense of being a well-realized world. The show is meaningfully better about this, because the for-profit cultural elevation of "heroes" without a clear-cut exigence is both analogous to several dynamics in contemporary American culture and reflects the cultural idea of the superhero as shaped by the MCU.
As far as League of Extraordinary Gentlemen goes- I only ever got around to the first two volumes. But the entire point of those first two volumes is that the conflicts between heroes and villains are in fact just different groups of monstrous shitheads working at cross-purposes- as is the nature of Victorian great-game politics. The twist at the end of the first volume is that Fu Manchu, while evil, isn't actually meaningfully worse than the people who sic the quote-unquote "heroes" on him- but he is foreign, and thus easier to paint as a legitimate target.
Then, in volume two, individual heroism very pointedly plays a very limited role in the defeat of the Martians. They're driven off Mars to earth in the first place after years of warfare with a guerilla coalition of several other fictional Martian species of note- led but not defined by the efforts of John Carter and Gullivar, and it's ultimately a lukewarm, unsatisfying victory. The League's involvement in the Martian situation actively causes setbacks at first because it puts The Invisible Man in a position to sell out the entire defensive strategy to save his own hide. Nemo is only able to provide an effective stalling action because he's assisted by his sizable crew. Hyde is the only one of the group who gets to do a traditional singular superhero moment, and he's motivated to do it entirely by his overwhelming desire to kill stuff over anything intrinsically heroic, and he dies doing it. And the tide is ultimately turned by black-ops germ warfare perpetuated by the English government, ultimately bringing the entire conflict down to the level of two packs of imperialists taking swings at each other with countless innocents caught in the crossfire.
(Man, I forgot how much I liked Nemo in these, by the way. Had to quickly reread both volumes in order to make sure I wasn't going to be talking out my ass, so thank you for motivating that. What a cool guy.)