Why open source?

I like open source projects, because I do believe in right to repair. I have a pen for writing, a keyboard for typing, and an iron for soldering. I use them to write novels, develop code, and to create real devices that are useful to me. Be it hardware or software: I need it, I use it, I improve it. Paid or free? I can pay for freedom. I want to buy products that are free for customisation. I don't want a car if I can't change a light bulb myself - that would not be my car.