I use 3 in 1 oil, just cause the bf said to 'cause that's what he's been using the last 20 years or so. Not having laid any other goop on my chain, I'm not worried about it being lifted off by 3-in-1 oil. I can't say I've noticed my drivetrain or any of his wearing any faster from it. I've definitely never had the stuff evaporate - I also haven't had it wash off. But I don't do an awful lot of wet riding. I get caught in a thunderstorm or torrential downpour periodically. Riding through several creeks doesn't seem to wash it off on a mountain bike.

Chains get cleaned and re-lubed periodically.

I just googled around - lots of people using it on their bikes, lots of people telling them not to. Can't say that I've tried anything else, maybe my bike would be faster with something bike specific.

Now, an advantage I see to using fancy stuff is you might not get black grease on your legs if you touch the chain.