What you said made me think that it's similar (not entirely the same, but adjacent) to those make-a-website for $XX or buy-a-template era of websites.

If we think about that as the intended competition (and not websites corps spent millions on design/polish/copy), I'd argue that AI (model + coding agent + skills + whatever) is doing a better job overall. Most agencies don't spend enough effort in understanding what you want, or hire juniors and bill them as seniors. It's almost always late, overbilled, somewhat what you said you wanted but not really, and technically terrible.