I agree. I think it depends on the context, though. I still use 3.5-turbo for text generation, content, ideas, etc, where it's completely suitable, fine, and even quite good.

However for any coding, complex analysis, or problems requiring calculation, there's no substitute for GPT-4. It blows 3 and 3.5 out of the water for code analysis, generation, debugging, and self-healing.