My software has only Makefile, but it works on both Ubuntu 20.04 and Debian 11.
The Makefile calls meson & ninja & npm.
I tell macOS users to install VirtualBox and then build my software inside.
I tell macOS users to install VirtualBox and then build my software inside.
Makefile-that-calls-3-other-build-systems isn't really using Make to build, is it? You are using Make as a glorified batch file. Could just as well use bash.
> I tell macOS users to install VirtualBox and then build my software inside.
This is pretty much the textbook definition of "non-portable build"
It is not nice on older as you can relatively easily make things work on most Unix systems if you don't use Linux specific calls.