It's still a lot given that when targetting the entire world (especially either mobile links or portions of the globe that don't have a CDN a millisecond away), a typical assumed link is on the order of 512 kbps bandwidth with 100ms RTT. That's two and a half seconds to load just your framework with a cold cache and without including any content.

Yes, many web developers are just targeting their own areas and test on high-speed links and everything seems fine, but frameworks that aim for widespread use still need to care about every single byte.