In the world of sitcoms, Seinfeld is one of the greatest ever made. The "show about nothing" catapulted itself into blazing fame, mainly because of its unconventional depictions of daily life. Nothing really happens in Seinfeld, nobody changes, nobody grows as a person, it's just one brilliant observation after another.
Among the main characters, George Costanza stands out as the most pathetic. In fact, he even takes pride in his lack of accomplishments, once stating that "My father was a quitter, my grandfather was a quitter. I was raised to give up." Given his usually putrid personality, there are a few things he has done that would absolutely not work in 2020.
His Homophobia
In the first season, George is uncomfortable sitting between Elaine and Jerry in the car, because "Boy-Boy-Girl." Elaine scoffs at his embarrassment, telling him that he's a little "homophobic, aren't ya?"
In "The Outing," George and Jerry are mistaken to be a gay couple, something they try their hardest to disprove, "not that there's anything wrong with that." This sort of subtle homophobia in TV and film is detrimental to queer communities, which is why it's not really done anymore.
Bizarre Fashion Choices
George hates his receding hairline, always finding the strangest methods to solve his hair crisis, from wigs to Chinese hair cream. His outfits are quite average, typical of heterosexual American men in the early '90s. Except, of course, when he brings up his ambition to swathe himself with velvet (which he is unable to do, being a strict consumer of social expectations.)
George's interest in appearance is only rivaled by Kramer. Unlike Kramer, however, he harshly judges people (his ex, Patrice) for their own sense of style, making him a hypocrite on top of everything else.
General Treatment Of Women
George loves women, but he doesn't really know how to get them to like him. In response to his many failures (and, on several occasions, times of success) he goes on frenzies of insecurity, worsened by the inevitable mixing in of paranoia.
If he approached women in the current era the way he does in the show, he would be treated with mocking rejection at best — and having the police called on him in the worst case. And for good reason, too: Women openly reject the notion that aggressive wooing tactics are masculine; while they never actually were, women are able to talk about it freely only now.
Everything He Does To Susan
Poor Susan. After everything she does for George, he ends up killing her with his trademark blend of stupidity and cheapness. His destruction of Susan's life begins much earlier, though, starting with getting her fired from NBC because he kisses her in full view of her superiors. He gets tired of her soon after, intentionally grossing her out via nose-picking so she would dump him.
In a few years, he sees himself dying alone, and begs her to marry him. She accepts, but George promptly chases after Marisa Tomei instead. Finally, he buys low-quality wedding envelopes whose glue was allegedly toxic: Susan licks an unhealthy number of these, and the rest is history.
Being A Total Coward
George dates a single mother, Robin, with an adorable little boy. During the kid's birthday party, a minor kitchen fire erupts: George takes one look at the billowing smoke and bursts out of the hall screaming "Get out of my way!"
This act is made so much worse by the fact that he pushes both children and an elderly woman with a walker to the ground in his haste to save his own skin. Robin dumps him almost immediately, but he wheedles a second chance out of her with the classic Costanza whine. Unfortunately for him, his nature is immutable; he sees a comedian with a prop gun and flees in panic yet again.
Obsession With Restrooms
This is the sort of kinky sub-taste that went out with the excesses of the eighties (along with going shirtless while pooping.) George's ion for bathrooms is so great that he quits, then gets himself fired after pretending he never quit, because his boss wouldn't give him access to the private bathroom.
He is proud to know the choicest NYC public bathrooms, which is proven when he shows Kramer the most perfect restroom in the city. George happens to be the kind of man whose burdensome self-doubt emerges in the form of highly obsessive interests (to the addition of his many, many neuroses.)
Professional Irresponsibility
George and Jerry have opposing ideas as to what it means to be professional. Jerry never misses a gig, always has new material and is generally very pleasant to be around. He starts off as a real estate agent, getting fired for mouthing off at his boss and later drugging him. George is also fired for having sex with the cleaning lady (in his office!)
He is a mediocre employee at the New York Yankees — trying to avoid work by parking his car at the stadium to make it look like he was in and creating a nap zone below his desk, among others.
Charity-Based Scams
Of all the innumerable ways George has come up with to save his money, the Human Fund is the literal worst. He invents a charitable organization with a most unimaginative name, scamming $20,000 out of his boss at Kruger Industrial Smoothing.
When he is discovered, he claims to have done it to avoid Christmas, as his family celebrates a holiday known as Festivus. Fortunately for him, this fact is proven when he takes Mr. Kruger to the Festivus dinner (although George would have not gotten off lightly if his company policy was not a total joke.)
His Shameless Demands
George is known best for offering nothing but asking for everything in return. At the same time, he tries his hardest to prove himself right, which is pretty much the only time he actually does any work. In "The Couch," George wants to prove himself a learned man by ing a book club.
Instead of reading Breakfast at Tiffany's, he decides to coast by watching the movie, but the only copy has been rented out. George sneakily finds out who the renter is, stalks their home, begs them to come in and watches the film with them. Then he acts like he owns the place, before getting himself booted out. It would be so much worse for him if he tried to pull such a stunt today.
Sex With His Cousin
To be fair, George doesn't actually have sex with Rhisa, but only pretends to (if that makes it better, somehow.) In "The Junk Mail," he tries to get back in his parents' good graces by acting like he and Rhisa are in a relationship.
Things get more complicated when she shows an active interest in carrying it on further, which George curiously neither rejects nor accepts. The sight of George's parents having sex cures Rhisa of her desire for George, saving everyone the inevitable embarrassment that would arise from this situation.