The search being free is half the reason. Or maybe 1/3. The other reasons are that in plenty of cases it takes more than when I'm trying to understand something and I'm not sure what (like, today, I was trying to understand how the circuit of sewing machine pedal works) and I had to do several searches in order to figure that out since I wasn't even sure what is the right term.
The other one is that I'm not native English speaker, and often, I search for a term in one language, then the other. Or I need to do a search, just in order to find the right term.