Great online experiences involve quick loading, no annoying ads, and other things. By forbidding various web technologies, the AMP (Accelerated Mobile Pages) standard generally helps produce better pages.
The AMP standard is meant to support user-first websites.
If you create a website that conforms to the AMP specification, you get the benefit of your website being stored in the Google AMP Cache and loaded faster in Google Search.
The Google AMP Cache stores copies of AMP websites. The AMP Cache typically loads much faster which helps provide a great user experience.
Each time someone accesses an AMP page from the cache, the cache is automatically updated with the fresh version ready to be served next time someone accesses it from the cache.