Letting people share their cars for riding incur increased risks, at least insurance should be different from a family's car who has the usual riders and the odd trip with other people vs a car which is being share with hundreds to thousands of different riders each month. How do you, as a government, ask for a different insurance class in this case? Regulation.
Same with Airbnb, having some guests over from time to time it's just usual life, hosting people to make money is a business and the business of hosting people has different rules than having a guest at home.
We can debate if such rules should be relaxed, if they make sense or need to be updated, etc., but these rules were created out of necessity through time, just allowing some tech company to completely sideline it because "it's tech!" is absurd...