I think a part of it is the difference to losing to something "reasonable" vs "unreasonable."

Yeah, that's understandable. I just don't think there's an equivalent in LoL that would feel particularly unfair. At worst, someone just knows where you are at all times. What do you do with that information? That requires good game knowledge. You can only influence a small portion of the map yourself and teammates tend to like acting independently even if you provide them with extra info.

Smurfing is a bigger problem, but I've found that Riot tends to be very good at gauging your skill level even if you intentionally sandbag. LoL is just one of those game where it's really hard to convincingly pretend to be bad at it.