There's good margins in any software that people want to use. There's money in Nextcloud hosting, Matomo services, or Bitcoin. All of which are open source projects that attempt(or attempted to) put power back in hands of users. There are many more examples.
VC will gladly fund a business model with solid margins. They often prefer those that might get a monopoly, grow exponential etc. sure. But it's certainly not the only mode.
The thing about software is it's remarkably cheap in the grand scheme of things. To choose two random modern examples, Signal and Lemmy both got their start with a little bit of funding from nonprofits. Signal then basically funded its bills with a Whatsapp consulting contract and now it pays for a CEO that goes around doing prime TV appearances where she shoots down politicians who are trying to rob you of your freedom. That's a hell of a story arc.
The customers want to donate money to local taxi operators and drivers?
The taxi drivers who barely understand what open source is?
This can work, but definitely not through crowdfunding. This better works through say business associations, say a national taxi association (composed of all small/regional taxi operators). That association can allocate a small portion of the funds to build this open taxi framework.
The truth is that I'd be happier donating to the project of a non-exploitative marketplace platform than tip a driver out of starvation while virtually all of the nominal rate goes to making a unicorn golden.
