As I have said before, I was a big user of big tech companies' services. I also used macOS (and Windows before that) and proprietary software for mostly everything. I didn't really know what free1 software was and, if I was running any, it was by coincidence.
At college, I discovered the world of GNU/Linux. I had an old computer that was very slow and someone promised that GNU/Linux would make it significantly faster, so I installed Debian next to macOS. This way, every time I turned on my computer I would be able to choose which operating system I wanted to use, and if something happened to my GNU partition, I could still use the computer as before. Even with Debian installed, the computer eventually started to become too slow for my needs and I bought a new computer where I also installed Debian next to the default OS. As for the old computer, I eventually erased both partitions and installed Manjaro with XFCE instead, I don't use it much anymore because of its limitations.
Progressively, I learned more and more about free software and I decided to use the Debian partition nearly-exclusively. Ultimately, I got used to the new desktop environment, the new tools (the terminal!) and all the new different things you find in GNU/Linux. There has been an interesting side effect of using Debian as my daily operative system: most of the software I now run is free/libre as a result of it.
I always thought free software was either worse than the proprietary alternative or non-existent for a given task. What I have realized is that there are free options for most of the use cases and that once you are used to the terminal, they can even be easier to work with, work faster and be more reliable. Moreover, they normally2 are also lighter programs, use fewer resources and generally follow standards (whereas proprietary software creates its own protocols/file types more frequently).
Don't get me wrong, there are advantages to proprietary software. It can sometimes work better, be nicer or more intuitive. Maybe it just suits your needs better because it's what you are used to. There may be commodities we are familiar with in proprietary software that are hard to let go of. However, in my case, it has gotten to the point that it is the other way around. It is hard to let go the easy installation process of free software, without license complications, the fact that it is available for GNU/Linux operative systems, the community around the software, the minimalism of the tools that get the job done, without the need of thousands of extra features.
There is a whole world of efficient and useful software that I had never really explored and I now see why so many people use it. I no longer look for free/libre alternatives to a proprietary program, but it is the only kind of software that I look for. Dealing with closed source and proprietary software is now my plan B, when everything else fails.
Firstly, in this post I claim certain qualities of both free and proprietary software. It is always spoken from my experience and perspective, your experience may be different. They are also qualities that I commonly find, instead of a claim that all software on a given category has them. Secondly, I deliberately left aside the ethical component of free software, as it wasn't what I wanted to talk about, however, you might be interested in reading more about it.