I'm saying that supporting multiple ABIs has a nonnegligible cost, regardless of whether the hardware supports it or not. On my MacBook (I haven't touched an iO

I'm saying that supporting multiple ABIs has a nonnegligible cost, regardless of whether the hardware supports it or not. On my MacBook (I haven't touched an iOS device in the last 5 years), the 32-bit dyld_shared_cache is 300 MB, and the 64-bit one is over 600. There might be baked in assets that are larger on the laptop form factor, and libraries that don't exist on the phone, and demand paging might buy you some of that back, but it's still going to be an absolutely massive chunk of code. I'm not actually arguing that this is a net win for the consumer of the device. If your choice is between a device that supports 32-bit and a device that doesn't, with literally zero difference in performance, I would totally agree with you (modulo engineering effort it takes to maintain them all, but that probably isn't too high). I'm just saying that there are real quantifiable benefits to what they're doing. edit: and that's not considering the actual advantages of forcing 64-bit like improved security via better ASLR