Owning a light aircraft is really no different to owning a car.
How many people would contemplate sharing their car with a group of others?
Very few I would suggest.
Same goes for an aircraft.
I own a 6-year-old Tecnam Sierra and the annual running costs are only marginally more than operating my elderly Mercedes.
Might be different for a top end machine or an elderly spam can but the new generation of LSA's that run on mogas are a different proposition.
They're also much more fun to fly.