But this is wrong. It was not rendering that killed other browsers. Rendering isn't the hard part. Getting most of rendering working gets you about 99% of the

But this is wrong. It was not rendering that killed other browsers. Rendering isn't the hard part. Getting most of rendering working gets you about 99% of the internet working. The hard part, the thing that killed alternative browsers, was javascript. React came out in 2012, and everyone was already knee-deep in earlier generation javascript frameworks by then. Shortly after, Google would release the V8 engine which was able to bring the sluggish web back to some sense of usable. Similarly, Mozilla had to spend that decade engineering their javascript engine to claw itself out of the "Firefox is slow" gutter that people insisted. Which is funny because if you had adblock, I'm not convinced firefox was ever slow. A modern web browser doesn't JUST need to deal with rendering complexity, which is manageable and doable. A modern web browser has to do that AND spin up a JIT compiler engineering team to rival Google or Java's best. There's also no partial credit, as javascript is used for everything. You can radically screw up rendering a page and it will probably still be somewhat usable to a person. If you get something wrong about javascript, the user cannot interact with most of the internet. If you get it 100% right and it's just kind of slow, it is "unusable". Third party web browsers were still around when HTML5 was just an idea. They died when React was a necessity.