The rise of targeted advertising is the main culprit of bad UX.
Everywhere there's dark patterns, performance overhead, mandatory updates degrading user experience, unnecessary JS and walled gardens breaking accessibility/compatibility, online-only etc.
This mostly matches up with the "business > users" point that the author was making. Businesses have decided that degrading the end experience for users through dark patterns, mandatory updates, walled gardens, and online only services is acceptable because users either have to use their product (electric companies, as an example), or because they offer a genuinely compelling product that people want to use despite the terrible experience (another point the authors made).
For performance overhead and unnecessary JS, that sounds like poor development practices that happens to also degrade the end experience for users, although some of that unnecessary JS could be some sort of tracking implementation that was included through business requirements.
Everywhere there's dark patterns, performance overhead, mandatory updates degrading user experience, unnecessary JS and walled gardens breaking accessibility/compatibility, online-only etc.