The concern is not about GPT-4. It's about what 10 years of research gets you to when, five years ago, it seemed completely apparent that even GPT-4 was 50 years off.
But I'm not talking about the GPT-4 either. Many decades and billions poured into research still didn't give us autonomous driving and there is no clear path how that should happen. So I'm not really holding my breath for anything even more capable.