No wonder, what did you expect?Software upgrades get worse for older hardware.
Software upgrades get better with newer hardware.
Seems to be the case with ios & iphone

Either that or Apple really did increase CPU performance by that much in the last couple years.Possible...this is just another scam to get people to ditch old hardware a less than 2 years old to keep buying another phone.
No it isn't, lately newer Intel x86 CPUs are getting only maybe 20-25% faster year over year. So some new OS feature won't kill an older MacBooks performance completely.Isn't that the case with any hardware/software?