Ask HN: Can you use apache cache for templating engine?

For a while I built websites by copying the same files/folders into directories... seems pretty wasteful for example if every page uses the same layout. Now it occurs to me I can echo out MySQL data that has the website itself in there as text. But even that is slow, I think it could be as long as 300ms, I should test it... I was looking at this briefly watching the network console tab in Chrome. I am somewhat aware of templating engines like Twig. I know I'm working with ancient tech regarding LAMP. I have not touched webpack/node yet. I was just starting to read up on Apache's cache and I was wondering if this was a dead end/not the right way to go. I saw that you could load files something about "stale"... My question doesn't really make sense because you still have to inject the content. My one attempt regarding PHP/MySQL echo was to concatenate the parts like: head-section + body/modular + close document. It works, though I have to see how fast/if it's better. It is better in not having redundant code.