Corey Doctrow has a good term for this, or at least it’s him i heard say it: enshitification. I think it just captures the dynamics beautifully, it’s almost poetic.
Ah, yes. Cory Doctrow. One of those people everybody hoped was full of shit and/or irrelevant 20 years ago, who, sadly, turned out not only to be right, but completely relevant (c.f.https://StallmanWasRight.reddit.com)
That's a great word, but wouldn't just plain "shittification" be better?
I think it's better as "enshitification". Where "shitification" would probably be a noun (like "relocation"), "enshitification" then becomes a verb to carry out that process (like "endanger" to "danger").