The real reason is that there are free alternatives. For many people, “free and open source” is the same as just “free”.
Again, I can fix most things on my car. I can afford the tools needed. But I don’t want to because opportunity cost.
One thing I have always found weird is the whole, “hey can you look at my computer? It is all slow” is considered okay to ask anyone in IT, but it (at least in the circles I was raised) inappropriate to ask a mechanic in the family to work on your car, the accountant to do your taxes, the plumber to replace your toilet.
And even with mechanics, some like to work on specific cars as a hobby, much like an engineer might want to play around with ML and work on a CRUD app for pay.