I... don't understand this. I've been using exclusively mechanical keyboards since the very early 90s, and I've been using nearly-exclusively Macs since the very early 2000s. I've never had an issue here. Mechanical keyboards, as a general rule, are programmable, and have swappable keycaps. It's a simple matter to swap the keycaps if you are adjusted to the Windows mandated keyboard layout ordering and how that's mapped automatically in macOS, or slightly more work to remap the keys /and/ change the keycaps. That's not even considering that some of the greatest pre-built mechanical keyboards in the 90s and early 2000s were Mac specific, like options using Alps key switches for instance.
There are many many many many mechanical keyboard options to use with a Mac. If you're legitimately having difficulty finding a solution, feel free to reach out to me via the contact information in my profile and I'll be happy to make some specific recommendations.