Can I ask those who are so critical of these cost sharing matching services how many Wingly / Skyuber flights have you personally done? What problems did you actually have?
Whilst all the dire consequences you describe are theoretically possible: can you quote a single instance where such a problem has actually happened in all the hundreds, or maybe even thousands, of cost share flights that have been done?
As I indicated in my earlier post: I have done several of these flights, stopping only when the FAA proscribed them, and never had the slightest problem.
Yet again: cost sharing flights are entirely legal and, in CAA and EASA land at least, the mechanism by which they are arranged is irrelevant.
Does that guarantee that nothing will ever go wrong on a cost share flight? No. But given that they are legal, ordinary pilot insurance will apply and, as I said above, how many such accidents have there been so far?
Does it guarantee that a pilot won't do something stupid? No. But the same pilot might make the same stupid mistake with a passenger who is not paying a share of the costs.
Does it guarantee that a rider won't have an unrealistic expectation of being able to fly regardless of conditions? No. But I described how I used to deal with this in my earlier post. I never had a problem with the flights I cancelled including when my plans changed even though the weather was fine to fly in.
Does it guarantee that someone won't try to abuse the rules and offer a taxi service? No. But if they do they should be dealt with by the authorities exactly as if they had put an ad offering an air taxi service in the Sunday Times or broken any other aviation rule.
In summary: these cost sharing services are legal, there is no great history of the kinds of problems suggested in earlier posts but those feeling uncomfortable with them are free not to use them.