I don't think OP is arguing against "self-contained components" (with template and code), but about "presentation and business code mixed". I really like Vue's

I don't think OP is arguing against "self-contained components" (with template and code), but about "presentation and business code mixed". I really like Vue's solution compared to React - the template is strictly separate from the logic driving the template. Same file, but seperate areas. I've previously updated some components in a design system to Vue 3, where I followed the HTML results set by the React implementation. Reading the Vue 2 components worked almost immediately. The React components were so over-complicated that I sometimes literally had to follow the browser inspector instead of understanding every twist and turn in the code. I have never seen a Vue codebase that is as unreadable as the average React codebase with mixed business and presentation.