You cut my paragraph in half, so missed the point.
All of it, glasses, legs, skinny was about the slime monster. You can not apply human aspects to non humans.
Plasmoids don't seem to have eyes as such, so a vision-correction prosthetic for them would probably look rather different than glasses for a human. I could definitely see a plasmoid using enchanted glasses, or purely aesthetic ones just to provide social cues to make humanoids more comfortable interacting with them.
My point about "fat" or "skinny" slime monsters still stands I think. They're impossible to judge by humanoid standards.
"Humanoid" is just the outward appearance of other PC races. It does not mean their physiology is identical. Vampures regenerate, why would they need glasses?
. . . because their nearsighted eyes are the ones that grow back each time?
Interbreeding of PC races is silly, unneeded in the game.
Half elves and orcs have deep roots in much of D&D including solidly established places in some settings.
This is all setting defined, and not even getting into saying dead weight in a combat is not going to work too well. There was in the past the wizard considered dead weight as after expending spells, the adventure was on pause until it rested to regain spells and not be useless. How does this work scaling a wall with soneone extremely over weight that everyone else must hoist their petard over?
To borrow from Men in Black, adveturers should be the best of the best of the best, and art should represent the adventurer, not the gluttonious land baron overtaxing his citizens. Not in the PHB at least, nor the monster manual. Robert the Glutton, should appear as art in his adventure to show players.
To borrow again from recent fiction, "to escape the zombies, you don't have to be the fastest you only need to be faster than the next guy."
It is not about depicting what a player would look like, but what a PC should look like in its environment. D&D does not have the football so Bill the technician sit in NORAD eating Dunkin all day waiting to push a button to send the launch code approval. It has "people" that must be in decent form to actually survived.
I think that you're incorrect on two fronts:
1: Realism: Different people naturally have different builds and levels of body fat and adventurers are no different. We're not talking obesity here, but the academic wizard having a paunch because most of their activity isn't strenuous and they eat well for example isn't unrealistic. They have a place in the party because they're valued for their ability with magic and their mind.
Most professional fighters that aren't required to cut weight to fit into a category have a healthy amount of body fat. The cut bodybuilder look popularised by Frazetta and Schwarzenegger to appeal to the men buying D&D isn't particularly realistic. (There is a reason that a lot of the swordplay in that Conan film looks somewhat stilted: Arnold was unable to perform some of the moves due to overdeveloped muscles.)
Showing a fighter on the other end of the scale, with more than the usual amount of body fat wouldn't be unrealistic.
Likewise the women: certainly IME, many of the most capable women in several fields of athleticism have been short and quite stocky for example, rather than all being tall and slim like much of the old artwork.
Showing people with more body types than the usual, rather than insisting that adventurers would all have "perfect" builds (using whatever your particular criteria for that is) fits fine within the setting.
(A chubby "couch potato" build might be a typical representation of having Str 8: unathletic, but not extremely so. A
lot of D&D characters are statted with Str 8.)
2: Representation: Many players and prospective players like to see inspirational and aspirational artwork of people like them because it shows that there is a place for people like them in the hobby. This doesn't necessarily mean that they want to play a character just like themselves, but that people like them exist in the setting. Not every woman's power fantasy is a lingerie model, not every POC's power fantasy is white, and not every fat person's power fantasy is skinny.
The existence of artwork depicting a diverse range of people within every lineage (rather than limiting it by saying "There are no overweight elves", or "You can't play a skinny halfling" for example) is essential for bringing more people into the hobby.
Lastly, while I doubt that the designers and art directors are deliberately trying to antagonise any demographics, I think it likely that anyone driven away from D&D by its depiction of "diversity" or "wokeness" is regarded as someone the hobby is healthier without.
"Judging people by how they look" I would guess.
Yes. And thus you can play it safe and continue to appeal to your established market, or you can take a risk and try to broaden your appeal.
I think that the risk is probably easily justified in this case. WotC could play it safe with old art styles, and based on this and the Wizard thread, there is certainly some pushback from established D&D players. However the number of the people complaining about the new art WotC is using to broaden its appeal seems to be quite limited. The intersection of "Is currently a 5e player", "Was intending to pick up the new 2024 5e", and "the new art is the dealbreaker that means they won't be playing 2024 5e" is pretty inconsequential compared with what they stand to gain by continuing to broaden the appeal.