Advantages using heading and text blocks over code blocks for SEO or load time?

I’ve learned a lot with using your theme over the last few months, and I was wondering if there’s any advantage to going back and replacing my code blocks with heading and text blocks (with simple classes) where possible? Would it help with search engines or loading time? I definitely need to use code blocks in many places, but I think I went a little over board with them during my build.

Thanks in advance for your time!