WebKit is a bad example, considering the KHTML history alone. These things don't just take devpower, but time - consider, for example, this: http://www.ekioh.com/flow
From what I understand, that team is relatively small in comparison, but actually does have this widely-ish deployed. So it theoretically could be done with less... but it's still insane to even consider. This isn't simple, and anyone who's trying to imply otherwise is wrong.
The other commentator you're responding with also never discloses they worked with Apple previously, while pretty much endlessly pumping up their work here. shrug
I was aware of Ekioh, but only tangentially; I had no idea of their progress so I didn't bring it up. I'd say it's great that they've managed to come this far. And to clarify if it wasn't plain from my other comments, I think that Chrome is the exception rather than the rule: it's an absolutely massive team. Possibly the largest of all the browser vendors that can make something close to compatible with the modern web. When pressed for an example I mentioned WebKit because just happened to be the by far the best example: it's the one that I could point to as competing with Gecko or Blink, plus it had a nice webpage I could link to instead of making people comb through Git commits.
They've managed to actually get GMail to render - a not insignificant task: https://www.ekioh.com/devblog/full-google-mail-in-a-clean-ro...
The timeline on this page alone is in years: https://www.ekioh.com/company/#team
From what I understand, that team is relatively small in comparison, but actually does have this widely-ish deployed. So it theoretically could be done with less... but it's still insane to even consider. This isn't simple, and anyone who's trying to imply otherwise is wrong.
The other commentator you're responding with also never discloses they worked with Apple previously, while pretty much endlessly pumping up their work here. shrug