I think it would be cool to have this kind of thing: AirBnB for Friends, but I don't think my need was a 'personal void' to be filled, just a function of being a social person with a socially unconducive job.
It may be a personal void for many (perhaps most), but shouldn't have to be.
[Edit:] Also, "wondering about dollar signs in people's intentions", yeah, same, but another reason that a specific transaction wouldn't be a bad thing.
A service to find someone to hang out with and show you around while traveling would end up becoming "Uber for Escorts" or some kind of Uber-Tinder hybrid.
For example Adult Friend Finder was started to actually find friends:
>In 1994, Andrew Conru created the first online dating site, WebPersonals. After selling that site in 1995, he launched FriendFinder.com, an early social networking site intended to help people connect with likeminded activity partners, in 1996.[3] Days after the site went live, Conru found that people were posting naked pictures of themselves and seeking partners for adult-oriented activities.
For better or worse, once I got into my mid-30s, I started wondering about dollar signs in people's intentions in general, unless I met them in the context of a hobby.