A real open source enthusiast will be always looking for open source alternatives in any platforms. It is not that difficult to get a free software for any platform. The Prism Break portal has a list of free software that can be used to save yourself from the notorious Prims surveillance program.
The macOS operating system is often considered as a platform for paid software only. However, there are hundreds of free applications available for the macOS as well.
Mr. Don Watkins has shared a list of free applications that he uses with macOS.
I use open source tools whenever and wherever I can. I returned to college a while ago to earn a master's degree in educational leadership. Even though I switched from my favorite Linux laptop to a MacBook Pro (since I wasn't sure Linux would be accepted on campus), I decided I would keep using my favorite tools, even on MacOS, as much as I could.You can read the original article and learn more on the listed in applications in OpenSource.com portal.
Fortunately, it was easy, and no professor ever questioned what software I used. Even so, I couldn't keep a secret.
I knew some of my classmates would eventually assume leadership positions in school districts, so I shared information about the open source applications described below with many of my MacOS or Windows-using classmates. After all, open source software is really about freedom and goodwill. I also wanted them to know that it would be easy to provide their students with world-class applications at little cost. Most of them were surprised and amazed because, as we all know, open source software doesn't have a marketing team except users like you and me.
The list published by Watkins includes LibreOffice, Handbrake, Firefox, Audacity, VLC, OpenShot ..etc.