Do websites with dynamic content actually need to stop browser caching?

Question

We always add nocache to our meta headers when dealing with dynamic content, but now that we're using html5, the old nocache meta tags are now invalid and we'll need to handle it via php headers. This got me thinking, why exactly do we even need to?

Answer 1

Static content can be cached, stuff like images, document and fonts.

Dynamic content should not be cached, since that would present outdated views to the user.

Note, that a page always contains lots of static stuff alongside the little dynamic content.