With such a low baseline, there is an optimistic perspective that LLMs could improve the situation. LLMs can produce excellent code when prompted or reviewed well. Unlike human employees, the model does not worry about getting a 'partially meets expectations' rating or avoid the drudgery of cleaning up other people's code.
AI certainly has the potential to make the underlying code/design a lot cleaner. We will also be working with dramatically more code, at a much higher rate of change. That alone will be a big challenge to keep sustainable.
The ones making the decision to under-invest on design are either are unaware of the real costs, or are aware and are deliberately choosing that path - that's not new, and I don't expect it to change.