I don't even get why it is important that it's 1kb. Give me a library with great API and easy to use. Nobody cares if library is 1kb or 100kb (minified).
Don't assume that everyone is happy with whatever level of mediocrity _you_ think is acceptable. It's because of developers prioritizing developer experience and other baggage over user experience that I despise my mobile web surfing experience.
Plenty of people do care about frontend performance (as evidenced by the plethora of efforts ranging from small alt vdom libs by solo devs to large corporate efforts like AMP or m.uber.com[1])
A large library is perfectly fine if it provides enough functionality to pull its own weight. But these days just about every site on the web has dozens if not hundreds of bloated libraries for the stupidest things and large bundle sizes due to that have become a pretty good indication of wrong priorities from the developer's part.
And I, as a user, am left waiting several seconds waiting for pages larger than the original Doom executable to load. It's gotten so bad that my wife had to be selective of when to use her phone because browsing normally without wifi from starbucks etc would get her over the plan limit by mid-month. I mean, how much browsing are you really supposed to be able to do when every page is several MBs of JS alone, and you have a 300MB/mo plan to work with? Not every country has cheap/good mobile plans.
Loading time doesn't always result in complaints (that depends on the user's expectations) but has a significant effect on likelihood of repeat visits, length of visits, and amount of interaction.
Plenty of people do care about frontend performance (as evidenced by the plethora of efforts ranging from small alt vdom libs by solo devs to large corporate efforts like AMP or m.uber.com[1])
[1] https://eng.uber.com/m-uber/