You can use Kirby to create high performance websites
One of my slight worries in starting to use Kirby was whether I would be able to create very high performance websites. Turns out, I needn't have worried.
When I started moving my sites to 11ty, one of the main reasons was to gain more control of their performance. And it worked. 11ty is brilliant, and a great fit for many situations. 11ty generates static HTML, so nearly all the computation goes into initially generating the site, while once its up and running it's incredibly efficient. I use it for my personal website, and I'll keep using it wherever performance is critical.
Now to be clear: Core Web Vitals aren't the be-all-and-end-all and there's a lot of work to be done optimising this site for people rather than performance metrics systems. If this website suddenly grew, both in terms of content and traffic, I would probably need to think about further optimisations to maintain performance. But Kirby is clearly a great tool for both creating websites with a fantastic editor experience, and websites that can perform at the highest levels.
The Intentional Technology Newsletter...
... will help you use technology with focus and enjoyment.