Here are some benchmarks on Apple laptops in Geekbench 4:
Fastest MBP in 2010: 2314 single core, 4525 all cores.
Fastest MBP in 2017: 4625 single core, 15535 all cores
Percent increase in 7 years: 99.9% single core, 343% all cores
Here are some benchmarks on Apple iPhones in Geekbench 3 (No Geekbench 4 results were available for iPhone 4)
iPhone 4 (2010): 206/206
iPhone X (2017): 4312/10585
Percent increase in 7 years: 2093% single core, 5138% all cores
They are not increasing at the about the same rate.
And your proof that Apple couldn’t switch from Intel to Arm is that RISC and CISC are different. However, as you yourself pointed out, they’ve switched between RISC and CISC in the past. So that’s not a very strong argument.
You say that the tech isn’t ready, but that’s precisely the claim that you have to support. Are you seriously saying that one of the top chip teams in the world, with the advantage of a 7nm process (compared to Intel’s 14nm) and the resulting efficiency in both electrical usage and heat reduction cannot make a chip better than Intel? I think that’s probably not right, especially given the fact that they’ve already surpassed Intel’s single-core performance on the iPad Pro, using much less electricity.
The best arguments against Apple doing this have nothing to do with the tech “not being ready.” That’s precisely why they would do it—because Intel’s tech is not ready. They are just plain unable to get their chip production going under 14nm, which is a huge problem for Apple and other PC companies. No, the best arguments probably have to do with the number of chips Apple would need to design and maintain and update, along with the possibility of losing access to things like Thunderbolt or other Intel IP.
Just my 2 cents.