https://wccftech.com/apple-mojave-is-the-last-macos-release-to-support-32-bit-apps/

Apple confirmed yesterday that macOS Mojave is the last release from the company to support 32-bit apps on the desktop.

Apple dropped the hammer against 32-bit apps with the release of iOS 11 by supporting only 64-bit apps and devices. Though Apple shoved in warnings in iOS 10 suggesting that the end is coming for 32-bit apps, but it was a clear sign that Apple would carry over such a movement to its desktop operating platform, macOS.