I mostly use it for Andy, an Android emulator from. I don’t do Windows, but VirtualBox lets you work in Linux, FreeBSD, FreeDOS, other versions of macOS, and perhaps even MorphOS and other less-well-known operating systems. The best low-end virtualization solution is VirtualBox, a free virtualizer for modern Macs.
Boot Camp and then virtualization apps made it easy to run other operating systems on Intel-based Macs.
Mac sales have been growing ever since Apple moved from PowerPC to Intel processors, in no small part because that made it possible to run Windows on Macs at full speed.