Also, people love stuff that will look like an "app" in their macOS dock. I maintain https://github.com/jiahaog/nativefier , which will make regular websites into "native desktop applications" based, obviously, on Electron. Yup, we've come full circle :D

I'd offer a counterpoint to folks asking that question: if you love webpages so much, why don't you do write all your code in Cloud9 in your browser? See, sometimes, a separate window brings a different feel and lots of nuances that matter :) . Maybe you don't feel those nuances, so you prioritize other axes (like resource usage), but some people do.

(Also, I routinely close browser windows I am not using by force of habit, which means I'd need to wait a load time every time I want discordapp.com.)

Apps such as discord & slack run in the background for me all the time. If all of them were in the browser each one needed a single tab for itself.

It has other benefits such as switching between windows via alt+tab and co.