iOS is 64-bit. macOS is on the way. Samuel Axon on 32-bit app notices appearing on the Mac:
macOS users will begin seeing notifications informing them that 32-bit apps will not be supported in a future version of macOS…
Apple began the transition to 64-bit hardware and software technology for Mac over a decade ago and is working with developers to transition their apps to 64-bit. At our Worldwide Developers Conference in 2017, Apple informed developers that macOS High Sierra would be the last version of macOS to run 32-bit apps without compromise.
I run a few legacy applications which will not be upgraded to 64-bit. Adobe’s Fireworks, I’m looking at you.