The pickle slicer was fired also.
I think the OP has just lost some of his sense of humor. No premise for a joke is old, if it is still funny.
I wouldn’t want to pay to see a comedian tell knock knock jokes, but then, I don’t go to comedy shows. But tell me one at work, and if it is funny, I’ll laugh. MOO!
I loathe twisted, contorted, contrived stories that lead to a horrible pun/word play on a well known phrase. These should be considered crimes worthy of lengthy incarceration.
Ah, yes: feghoots.
Not a fan of Asimov, I take it.
For most of those setups, I can think of at least one joke that still holds up, even blonde jokes (the one about the Brazilian guy). I guess knock knock jokes hold zero interest for me, but a five year old might not have heard it, so there’s a reason they’re still in circulation.
For the Soviet Union ones, I think the Yakov Smirnoff template that spawned a zillion memes is just pretty old and tired now. I do know one Soviet Union joke that I think still holds up; I told it to my uncle who used to work for the FBI and was for some reason sometimes assigned to the 'stans, and he loved it. I got it from a P.J. O’Rourke article:
(set during the waning years of communism in the USSR, sometime in the mid-80s)
Yevgeny is in the bread line one snowy afternoon. After hours of freezing and waiting, the shopkeeper comes out and says “I’m sorry, there’s no more bread today.”
This is the final straw for Yevgeny (who’s been going through some stuff). He starts to rant. “No bread? Again? I give up! How do we accept this? Where’s this worker’s paradise we’ve been promised? Who are they kidding? They can’t even provide basic necessities, and we’re supposed to believe this is the greatest system on earth? This is a failure!..”
Out of the crowd comes a quietly sinister-looking man in a trenchcoat. He sidles up to Yevgeny and whispers in his ear. “Comrade, please calm down. Walk with me.” and he leads Yevgeny away to a nearby alleyway.
“You remember, Comrade, what would have happened to you in the old days if you were to be heard saying these things.” and he mimes a handgun. Yevgeny composes himself, and nods. The man sends him on his way.
Yevgeny arrives home and his wife says to him “What? Don’t tell me they’re out of bread again!”
“Worse,” says Yevgeny. “They’re out of bullets.”
I listen to a lot of comedy radio. They do mostly newer stuff, some classics and the occasional older bit. Some of the Sam Kinison stuff, say, shocking in its day, is amazingly so given modern sensibilities.
Elephant jokes were a brief fad in the early 1960s.
How can you tell when an elephant is in your pantry?
He leaves footprints in the peanut butter.
Best I can figure, Polish jokes died out in 1980 with the rise of Lech Wałęsa.
They were still around when I was a kid in the 1970s.
A few I remember off the top of my head:
Why do elephants wear red tennis shoes?
So they can hide in cherry trees.
Have you ever seen an elephant in a cherry tree?
See, it works!
How is an elephant like a grape?
They’re both purple (except the elephant).
What did the grape say when the elephant sat on it?
Nothing—it just let out a little wine.
Why do elephants have flat feet?
From jumping out of cherry trees.
Doctor, it hurts when I lift my left arm. Don’t lift your arm.
Doctor it hurts when I bend my knee. Don’t bend your knee.
Doctor it hurts when I breath. Don’t breath.
Ha ha ha
Now, take my wife - please!
Uh oh.
So often, when there’s a list of three things, somebody feels compelled to make the joke (referring to the Wizard of Oz quote) “X, Y, and Z, oh my!”
Not so long ago, you’d be more likely to hear “X, Y, and Z? In this economy?!”
Located entirely within your kitchen?
Nitpick: breathe:
It’s more likely than you think.
Two.
A son and father were sitting in their fifth floor walkup, one of the good ones, with only one drafty window and heat that worked most of the time, and the son asked, “Papa, what will it be like when communism is perfected?” And the father answered, “Everyone will have everything they need.” “And what if there is no meat in the store?” "There will be a sign: ‘You do not need meat today.’ "
Shah Guido G!
The star-mangled spanner.
That guy ruined humor for me! 
“Star-mangled spanner” was Clarke.