Liability not withstanding (7-15 passenger capacity and beyond are classified and limousine / bus and require very expensive specialized insurance -- most must be bonded), and rules and restrictions aside, it's a bad idea. Uber and Lyft do not care about the driver and take as much as 50% of the rider fare most of the time, 30% at minimum. I cleared about $4/hr with a 4-banger that got 24-28 mpg around town. Imagine what it's like with a bus that gets 6-8 mpg (or less).
Now there are two different services rideshare offers, base (4 pass max), then there's premium, which is is over 4 passengers, but I think it's limited to 7, so a bus would still be out of the question. XL fares are only marginally better anyway. See more in this post
on how I break down the reality of it. Trust me, it's a rip-off for both the rider and driver, and it's definitely not a train you want to get on, especially using a fuel-thirsty vehicle like a bus.
And you really do meet some of the most clueless (and sh*tty) people on the planet. I had some idiot try to cram a bed frame into my Ford Taurus after I told him it wasn't going to fit. We're not moving vans, people. Quite frankly, rideshare passengers are not only notoriously cheap in not tipping, but coldly callous about the driver's lowly position (when they ask what it's like) and will on occasion even stoop to making false complaints and give undeserved poor ratings just to try to get a free ride, feeling that THEY make the rules when it's YOUR vehicle.
What's worse, rideshare companies give the driver no recourse when they get a poor rating under such circumstances, you don't even get a chance to tell your side of the story, when your rating only need drop below 4.7 from 5.0 to be deactivated (at which point you get to pay the rideshare company money out of our pocket for "improvement" training - for which you only get one second chance).
Did it for 2 years, was (un)lucky enough to have Miss Daisy slip her moorings and knock me galley west when I was in trip. Two years after that collision, I am currently furloughed for COVID on unemployment, and likely the only rideshare driver to actually have an ever-so-meager nest egg (from the insurance claim, it damned sure didn't come from driving rideshare), and I do not plan to go back if I can help it. There's a reason I gave up my own business as a taxi owner-operator to get a CDL and drive 18-wheelers, and if asthma had not forced me out of that, I would never have touched rideshare.