I genuinely believe OSS is great for sharing knowledge, but I also genuinely believe that no other industry out there has managed to play itself at this scale. Every single tool you want is made available for free by devs who burn themselves out writing free code to impress employers. Essentially, OSS devs have fought against corporate only to become trapped by corporate because now software has near zero value. Pretty illogical if you ask me. I'll buy a license for either of the two (postman or insomania), just because this crap needs to stop.
No, but I do code sometimes in my spare time or I am sometimes able to utilize my work time to contribute if it's functionality my company needs from an open source project we're using. It's not like you have to sign up for 8-hour shifts in open source software development.
All of my FOSS work has been either directly sponsored by my employers, or stuff I've done in my free time because I wanted to make a thing exist for my own purposes. I don't know anyone who's burned themselves out writing free code to impress employers, so I guess I just don't see it the way you describe.