Joey Sneddon over at OMG! Ubuntu! asked and answered the question of why someone would use LInux over Windows or macOS. His three-word answer leans a little close to zealotry, but is completely understandable. In my case, I've been 100% Linux on all of my computers for quite some time1 and rarely see the need to go back to either. While I can readily admit there are some applications that I miss from when I used to use macOS on a daily basis, going back to Apple's operating system is not something i'm prepared to do. Microsoft has made a lot of efforts to integrate Linux with Windows 10 but, even with the Linux subsystem functionality and Redmond's insistence that they love Linux, I cannot bring myself to allow any version of Windows to run bare metal on any of my machines. Like Joey, my reason can be boiled down to a three word answer: I trust Linux.
There are a lot of benefits of using Windows or macOS on a day to day basis. There's generally more commercial software available, faster driver updates, and better support for battery-related features. That said, I don't trust these systems. Same goes for Android. I simply do not feel it's in my best interest to put any data of value on a system that seems forever tethered to its creator, sending and receiving data as unobtrusively as possible in the background2. Linux distributions, as a rule, do not do this3.
Given the sort of data that I work with on a day to day basis and the trust people have put in me to not leak, lose, or share their data with anyone else, I need to completely trust my computers. Linux makes it easier for me to ensure that my systems are secure and non-communicative with unauthorized external resources.
There are undoubtedly a number of people who will disagree with me, and that's fine. While there are thousands of different distributions available to meet just about any need or criteria, the vast majority of people will be happiest on one of the two main commercial operating systems. This, too, is fine. It's not my job nor intention to convert anyone to Linux or provide the days or weeks of support that would be required while a person acclimated to the different system. Linux works for me. Specifically Ubuntu Linux. If someone reading this prefers something else, then it's better to continue using that software. At the end of the day, how we use our computers is a personal choice.
This is despite the unenforceable expectation that everyone at the day job is using Windows 10 with the various tracking and "security" tools installed … including all the Apple devices.
iOS also shares information back to Apple, albeit to a lesser degree. While I'm not keen on data leaving my possession without explicit permission, I generally know precisely what information is being sent to iCloud and can modify my behaviour enough to maintain some semblance of verifiable control.
The online "outrage" that surrounded Canonical's attempt to collect system information after a successful installation was seriously disingenuous. While there is the option to send anonymous system data to Canonical, it was an opt in function that would show you the entire message so that you could determine whether it could be shared or not. After a little more than a year, it turns out that the majority of people installing Ubuntu Desktop send the data to Canonical