A followup: The GNU project was born while I was in junior high, gcc started when I was a senior in high school. Linux was started when I was in college.
Stallman, in a very real sense, made my entire career possible. Likely yours too.
I agree with you that it's a jump. I was around early enough to see what the world was like before the FSF. While my professional career started after that, for much of it I worked with $5000k per seat compilers, libraries and frameworks that didn't include source code and I even accepted jobs (out of need) that forbid me from using anything without a restrictive (to the point of abusive) license.
I've seen both worlds. You don't want to be in that other one, trust me. What I will say is not that free software has made my career possible, more that it has made it possible for me to do my job without going crazy. No more reverse engineering bizarre bugs in my tools. No more building everything from scratch because I can't possibly trust anybody else's code. Not as much struggling to deal with boneheaded vendor lock-in that some executive in the nose-bleed seats commits me to (OK... it still happens... but it's a lot better).
I'll be honest, though. I didn't actually believe that the reality we have today, as flawed as it still is, would come. I'm incredibly grateful.
Could I have made a lot of money in software had the free software movement never started? Sure. Could I have had my particular career? Nope. Could the current world of a zillion startups enabled by cloud computing exist without the GNU project or something like it? Seems unlikely to me, but perhaps my imagination is limited.
People would be using software with or without free software existing but that's completely beside the point. Free software enables people to do computing. The fact that you can do computing at home with state of the art tools is something you can thank the GNU project for.
Stallman, in a very real sense, made my entire career possible. Likely yours too.