The new requirement states not only that sites must be built to be under 500 Kb, but also less than 50 requests.
In addition, metrics such as LCP https://web.dev/lcp/ basically means you need to rebuild your site from scratch with speed and these metrics in mind, or make your pages static by removing unused css and js code manually from your theme and plugins.
Removing that code, will mean you are loosing customization capabilities from your page editor in the future as well.
So now, you need to built sites without page editors and specifically catered to their metrics.
For example, a hero image loading above the fold that takes 3 seconds to open on mobile will increase your LCP… but if you paint it first, ex: set the background to the image size on a similar color before the image actually loads, then LCP will be low.
In other words, theme authors and plugins, need to create designs that consider this.
In addition, sliders that use javascript to load images must be avoided, especially if they are above the fold. Javascript execution time is one of the most significant things to consider now, so prefer designs without jquery.
I would recommend the Astra Theme for example, though if you are going to add elementor and addons, the code will grow up again and defeat the whole purpse.
You need budgets for css and js code.
If you build using a lot of plugins, heavy theme and editor, you can customize it and remove unused code. But removing it means it will be gone if you ever want to change the layout.
Also editing original files should not be done, as you won’t be able to update things.
To avoid document.write () you must disable the flter for PSI option. No other way around it.
Slider revolution looks great, but just using it without anything else on the page, immediately shaves away 20+ points on mobile. I would not use it.
Elementor CSS and JS files can be quite large as well. Try to stick with gutenberg only themes, when possible.
