http://www.anandtech.com/show/9837/snapdragon-820-preview/2 http://www.anandtech.com/show/9686/the-apple-iphone-6s-and-i....
Heck, in many cases the A9 leaves the Snapdragon 820 behind, and that hasn't even shipped in a Nexus phone yet (the Pixel will probably have the 821).
Apple could just drop new Intel chips into their existing MacBooks as they get released, and easily be getting improved speed + efficiency each year. The new Kaby Lake chips even do hardware 4K video and VP9. http://arstechnica.com/gadgets/2016/08/intel-unveils-kaby-la...
sigh
I think the real reason is some combination of (a) ARM isn't competitive (or only recently became competitive) at the high power/high performance point that Intel CPUs excel at; (b) the Mac line generates so much less revenue and operates at so much smaller of a scale than iOS devices that it isn't worth developing CPUs in-house for them, not to mention the fixed costs associated with undergoing a transition.
Dumping Intel chips would take a ton of effort and resources, in an area where Apple isn't interested in making an effort or investing resources.
Measuring browser performance is hard because there's a lot of different functionality but notice how routinely we see reviews where the device the Android flagship phones are trying to beat is the iPhone 6 or even 2013's 5S:
https://cdn.arstechnica.net/wp-content/uploads/2016/09/iPhon... https://cdn.arstechnica.net/wp-content/uploads/2016/09/iPhon...
(from https://arstechnica.com/apple/2016/09/iphone-7-and-7-plus-re...)
Some of that reflects the considerable amount of work which Apple has put into Mobile Safari but a lot of that is going to come down to single thread performance.
This is an empty statement backed by no data. The only evidence you provide to the superiority of single core perf is browser performance. Except,
1) browser usage is now a mostly insignificant part of time spent on mobile (http://flurrymobile.tumblr.com/post/127638842745/seven-years... )
and
2) The bottleneck in mobile apps which depend on the network (including browsing the web) is rarely the CPU, it's the network.