Honestly I can’t recall which gen dropped it, but presumably the moment they reached their EoL for the last non-64 bit device they had no reason to maintain the development cost of having a 32bit OS, maintaining support for communication between 32 and 64bit apps, nor the cost to users (doubling the size of the resident system memory, confusion of some apps running on some device but not others, etc).
And then knowing that if you drop 32bit then you can gain space on your silicon.
What irks me is that devs saw the first 64bit devices come out, and didn’t go “I should recompile my code”. Honestly the fact there are so many new apps made for pc that aren’t 64bit is mind blowing to me.
> Honestly the fact there are so many new apps made for pc that aren’t 64bit is mind blowing to me.
Assuming you mean Windows, there are still a nontrivial number of PCs in the wild that are running a 32-bit OS. It's not huge -- about 1.5% of gaming PCs according to the Steam survey, probably a bit higher for home and office computers -- but either way it's enough that building applications as 64-bit-only is problematic.
Are they 32bit cpus or 32bit windows? I recall windows inexplicably treated(treats?) 32bit and 64bit as being separate purchases for some reason (I assume money, given they limit supported core count according to which type of windows you buy).
But more seriously: why ship 32-bit only software. 64bit has been supported by all cpus intel and amd have shipped for more than a decade now. I had a consumer 64bit Athlon in 2005/6 that I could afford on a student budget. Given the perpetually increasing cpu demands of modern games, that you'd throw away something in the order of 15-20% perf by not support 64bit just seems insane.
Seriously: make 64bit your primary target, and if that hurts 32bit perf, that's those user's problem: they chose not to buy a high perf system.