Being a CPL with my own aircraft why would I? If any of my friends or family told me they were flying via this site though, I would try my best to put them off. Especially if it was with a low houred PPL.
Hours alone however are not a good enough way to measure, it's recency that counts. I would not like the idea of anyone I know flying with someone that has done the minimum hours and what is to stop that happening?
How much checking of recency and hours does Wingly do? When you pay for an air taxi or experience flight via a school you know that the pilot is in currency and proficient to carry out that flight.
Yes, cost sharing is legal but that is based on a flight that is being carried out anyway with an empty seat. The adverts on Wingly are clearly offering a service to suit the passenger and, as has been alluded to above, flights are being carried out that wouldn't otherwise be. The fact that the pilot and hiring organisation are making money is not a positive in wingly's favour but all the more reason why these flights are probably illegal.