I'm not sure about coders but for artists I don't think a massive number were making anime waifus, but instead were making graphic designs for advertisements, publications & websites.
Currently AI is actually replacing some of these jobs. But there's kinda a hitch there - when you target me with ads or show me your company's website and it has obvious AI art I tend to think that you're either selling me something very low quality or are a scammer. If you show me the novel you've written and it has an AI art cover I assume the contents are also AI generated garbage writing. So I wonder if those jobs will really be replaced? It all depends on society's acceptance of AI art and if AI art doesn't get any better. I thought it would get to the point that I couldn't tell it was AI by now, but so far it hasn't.
I think AI waifus and porn and memes and browser based zynga type games will be a place AI is going to be accepted because nobody cared too much about the authenticity and quality of those things before either. But an advertisement selling me a car? The cover of a book on philosophy? A website that I'm going to give my credit card number to? I'm not sure about those things.
Cars feels like a bit of an odd one out because there's basically no low end. If you have the money to produce even a single car from a Camry to a hummer, you are probably going to not try to pinch pennies on marketing because a single car sale pays the salary of a designer for a year.
We really should start being more precise when we say "replace". Are we talking about replacing 90-100% of that particular job? Or 50-80%?
Because it feels like people argue as if they were talking about the former, but if probed it turns out they admit it's the latter.
There will be still people making car advertisements, but they will be using ai tools and will get asked to produce X times faster. Effectively, some of them will get replaced, or rather have been replaced.