Also, afaik, there's no reason for hobbyists to not always use lead-free solder. But of course that doesn't mean something you're taking apart used lead free.
The leaded solder melts easier than non-leaded. This is good because you are way less likely to burn off traces or melt the board using a lower temperature iron. I only use leaded solder because I suck at soldering.
Repairing an old device that used leaded solder is a reason to use leaded solder (even new leaded solder during the repair). I don't even use the same tips across leaded and lead-free solder.
I think pretty much all consumer electronics uses lead free solder for the last 10+ years. The reason hobby users tend to use leaded is it's much easier to work with and they don't care about health or the environment that much.