It's tempting to be cynical but there are good reasons for this. The main good reason is power efficiency. As the seller of the device Apple is the chief party held accountable for poor battery life. You or I or other technical folk might point the finger at particular apps but the typical consumer will just bemoan the "poor battery life on my phone". Apple takes ownership of that outcome and if that means forcing it to be a priority for all browsers, so be it. It's what lets them advertise the battery life for web browsing that they do.
Additionally, I would like to challenge the unsupported notion that WebKit is "stagnation of web browser tech". While there may be issues here and there, my impression is that Apple is overall committed to pushing the envelope[1] and adding compelling features.[2]
Additionally, I would like to challenge the unsupported notion that WebKit is "stagnation of web browser tech". While there may be issues here and there, my impression is that Apple is overall committed to pushing the envelope[1] and adding compelling features.[2]
[1] https://webkit.org/blog/7122/introducing-riptide-webkits-ret...
[2] https://developer.apple.com/library/prerelease/content/relea...