I have worked at several AI/ML firms. Only in extremely rare circumstances do your problems require PhD level ML knowledge. But the amount of tech debt produced by 'scientists' is horrendous.
Can someone who studied CS 15 years ago and has since worked as a webdev produce robust ML systems? Probably not without significant training. But someone who has done a CS Masters in the last 5-7 years and has shown interest in the subject will run circles around a PhD who never had to write non-academic code.