I understand it to mean the general life cycle of corporations: first valuing users, then shareholders, then themselves, then dying. A quote from Doctorow:
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.
By that definition, everything you described is a likely consequence of enshittification (paying employees less, charging more, more ads, etc.). But the word itself refers to how the company’s values shift over time.