Based on my experience in the industry over the last 20 years I would suspect there is something faulty with the data you are basing this on. Particularly when it comes to US based startups and other tech companies. I've worked a dozen in that time and at every single one, the majority of developers (if not all) used Macs as their primary system. Certainly there were those that used Windows but often that was because they were developing drivers for Windows. At that brings me to the reason why so many developers have and use Macs. Until the transition to Apple Silicon, you could develop Windows software on a Mac (via bootcamp or parallels) but you couldn't develop MacOS or iOS on Windows. So if you wanted to develop for Windows, Mac, iOS, Android and the Web the choice was pretty easy, your only choice was a Mac.