This happens when you use a Ubuntu USB device to boot from. The wifi adapter isn’t recognized in this old(er) MacBook Pro 13". Well, I have other things to do anyway. 
@holgerfrohloff I was going to comment on this yesterday when you asked for advice. Finding a version and distribution combination of Linux that will work with the hardware you want to use can be a long and sometimes fruitless journey.
@walter Thanks for your comment. You are absolutely right. I tried to use Arch some time ago on Mac hardware and it wasn't fun. But I don't want to buy new hardware just for this cause. Because that doesn't make sense either, specifically not considering the environment.
@holgerfrohloff when I have periodically gone over to Linux I have found that buying a used Dell or Lenovo has given me better results. If you buy used, you’re at least not adding to the waste stream. I do mostly iOS work recently so I’m stuck, but I plan to switch when I can.
@walter using Dell seemed to be the best choice regarding performance, design and functionality. And it could save time as they even sell devices with Ubuntu pre-installed. Perhaps I find someone near me that sells used ones to businesses.