Alright here i go
Firstly, most people don't think that the verse caps anywhere near above Solar System level to possibly Galaxy level and that's including the chaos gods because they think that the chaos gods only exist in a single galaxy even tho old lore and the new lore suggest otherwise. Primarchs are literally treated as a joke, i once got literally crucified in a reddit post because i said that Sanguinius destroying a solar system sized structure was a legit feat that would put him around that tier and people literally called me a buffoon, manchild, and a ****** even even tho i showed them characters who can destroy planets and some other characters doing similar feats, they didn't ******* care. We are literally the only website who claims that the Warhammer 40k verse is even remotely higher than Low 2-C
Secondly, Abaddon is literally disrespected beyond belief... Everyone treats him as a meme essentially even tho the guy killed a ******* primarch clone ad people will claim that it isn't legit, and that goes to his other feats too. Everything he does is regarded as just plot armor or not even legit and he shouldn't be that powerful because... reasons. And that goes about to every other character
Thirdly, Even tho people say that Warhammer 40k is wanked in terms of infantry that might not be further from the truth. You see this is so ******* bad that some writers actually fall for this meme to the point where some writers think that Orks are equal to an average guardsmen and they get killed in close armed combat by them... to just give a perspective, an ork is always meant to be physically as capable as an Astartes and they can survive decapitation without much of an scratch because of their regeneration capabilities and comparing that to an average human is beyond idiotic. Not to mention people thinking that titans cannot survive nukes or terminator clad astartes being punctured by a guardsmen knife is possible because of tabletop logic's...
Fourthly, The Dark age of Technology for some reason getting downplayed? Yeah, when people learned of the interex they legitimately thought that most people in DAoT weren't as advanced as they thought even tho Speranza a ship that was created before the DAoT was able to ******* manipulate time in a way that not even a precognition eldar could predict it, create black holes, and manipulate literal void. I'm not even going to go over the other things that were stated to be in the DAoT but it's weird that it also gets downplayed as hell and speaking of advanced technology.
Fifth, Necrons. People only ever think about the Celestial Orrery even tho that's not the only thing that necrons have that can snuff out planets and stars. Most people tend to downplay C'tan a lot because people don't read a lot about them and in turn don't know anything about them so they don't know these are literally the gods of the materium meaning they have total control over infinite universes that is made out of infinite dimensions but it's hard to convince that anyone that warhammer 40k is above planet level let alone High 1-B. And people for this reason tend to think that wouldn't do well against other advanced civilizations such as the forerunners and xeelee because they think that the necrons cannot manipulate or destroy more than a galaxy even tho they managed to fight with the Old Ones (the guys who managed to easily beat he C'tan) and the C'tan at the same time and even win
Warhammer 40k while oftenly said to be wanked is more so downplayed than wanked and there is much more i could get into as to why the verse is so downplayed