Noticing when an app is only hosted in us-east-1
I don't buy this.Hacker News is one of the most responsive websites I know. And it is run on a single server somewhere in the USA. While I am in Europe.    If you have users in Sydney, Australia ... 
    ... you are floored at 104ms of latency for your request

When I open AirBnB with a clean browser cache, it takes several seconds until I see something useful. Those 104ms of latency don't make a dent.Reddit takes over 5 seconds until the cookie banner is ready for me to click it away.Twitter takes 6 seconds to load the homepage and display the single tweet which fits on it.    preview images take a little longer to load

Preview images of what? Images usually should be routed through a CDN which caches them directly in the user's country. It's extremely cheap and easy to set up. Nothing compared to running an application in multiple datacenters.