I recently came across this post by Cory Doctorow which I feel neatly captures what's been going on with the declining usefulness of a lot of big tech platforms. He sums it up in the opening paragraph:
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
The rest of the post provides a lot of good examples of this process in action, which makes it more useful than my general intuition of (old man yells at cloud voice) "didn't this use to work better?"
Also, it's just fun to say: enshittification
