#2 is the kind of system that's ripe for "disruption" (or whatever your favorite buzzword is for this). Is the answer specifically this app? Maybe not, but "pretty nice systems" don't tend to involve "usually", "chip in", or "common" (not to pick on your specific language, I just mean the "hidden" knowledge and customs that come with informal, organic systems).

It's that informal and inconsistent group knowledge that gets turned into an app, which formalizes the informal parts, removes the barrier to entry (knowing about the informalities in the first place), and (should) build protections in to ensure conformity to the now established system (payment, insurance, etc).