Cory Doctorow, on coining the term:
Here is how platforms die: first, they are good to their users; then they abuse their users to make things better for their business customers; finally, they abuse those business customers to claw back all the value for themselves. Then, they die. I call this enshittification, and it is a seemingly inevitable consequence arising from the combination of the ease of changing how a platform allocates value, combined with the nature of a "two-sided market", where a platform sits between buyers and sellers, hold each hostage to the other, raking off an ever-larger share of the value that passes between them.
The term was about online platforms degrading. This term described things like going to a subscription model, creating tiered subscription models, injecting more ads, and other practices to min-max short term profit on an online platform once enough customers were locked into it.
Since then a few examples I have seen referred to as "enshittification":
A movie sequel not being as good as the first movie.
A game sequel not being as good as the first game.
An unintentional quality defect on a one-time purchase of a consumable product.
A UI change to software (that didn't lock out previous features or change functionality) that the person personally didn't like.
The price of a new (luxury) product being higher than the complaining person would like.
A restaurant changing their menu.
A specific product being discontinued.
A TV show's writing getting worse.
The term has been so diluted it just means "a thing I don't like happened with any product or service."
There is another process at work here: semantic territorialization. A neologism was created by someone with a certain kind of knowledge. Doctorow has the kind of mental map of the world that comes from being a tech-focused author for decades. He created the term as a shorthand for a concept that is important within the domain he wants to discuss, giving a set of landmarks on his mental map that he hopes will transmit enough c0shared context to convey the shape of the territory. Then people who do not have anything like his level of experience with that area try to interpolate the space he has delineated on his map as 'enshittification' and think 'Uh... platforms... that's like what colleges do with Nazis, or something... and uh... customers... that's us, like me when I buy things at the store... and uh... fuck it, this is too hard. I'm taking the literal approach. En-shit-ifi-ca-tion... shitty-fy-ing... make shitty. Enshittification means make shitty. Too complicated. Enshittification means was good, now bad.' They strip out all the elements they can't understand and are left with a shiny new semantic territory (word) that makes them feel clever, despite revealing how little they actually understand.
It's incredibly depressing that language is such a godawful way to transmit meaning despite being the absolute best way we have yet discovered to transmit meaning.