Mentioned Glitch and Replit in the article - they're great and I love them but there's still something missing about relying on these platforms imho. I think cementing a default coding environment right into the browser would make it a lot more accessible - and actually be much closer to real coding where you're manipulating files and running code.
Plus: glitch/replit are quite slow to do any real coding inside of vs developing locally.
But maybe the future really is in the browser in this way.