> Larger bundle sizes are unfortunate, but they're not the main cause of performance issues. That'd be images and video sizes, especially if poorly optimized, which easily and immediately dwarf bundle downloads; and slow database queries, which affect server-side code just as much as browser-side code.

In network terms JS tends to be downloaded at a higher priority than both images and video so has a larger impact on content appearing

JS is also the primary main thread blocker for most apps / pages… profile any NextJS app and you’ll see what a horrendous impact NextJS has on the main thread and the visitor’s experience