This is an interesting article.
What I find very appealing about frameworks like Svelte is that it gives you most of the productivity boost of working in a framework, without paying the price of downloading a large runtime.
This is particularly helpful if you are building smaller page features and not a large SPA.
I have a practical example on my blog of this. I converted a commenting feature written in Aurelia to Svelte. The component was reduced from over 100k to about 4.7k.
More details here if interested:
I have also notices that Svelte has relatively decent compatibility with the closure compiler which might allow for further optimization.