I love the idea of sharing economy and, since I moved to a rural area, participate in it. Someone, somewhere, has this thing I need currently and they have in excess. Chainsaw, trailer, tractor, scaffolding, baby formula, really long stepladder, time, capable hands, knowledge. I also let people borrow my tools and offer advice/services. Most of the connections I made here were due to a random need and someone who has connected us knowing what the other party had on their disposal. I'm in constant awe experiencing how well it works without apps or platforms. But the crucial part is: no money changes hands in all this. You get something, you give something back to the community.
I have the feeling that the large-scale implementations of sharing use this social interaction as a ground to grow small businesses which offer services to strangers. I'm okay with that, it makes everything more efficient and straightforward, but there's little left of the sharing part of the deal: Hey, why not use your car that would sit in the garage while you waste time to make extra few bucks -> lease a new car and work as not-taxi-driver. Have an empty apartment or go for vacation, let someone occupy it -> get a mortgage for 3 condos and run a totally-not-a-hotel. Tools collecting dust in the shed -> buy a few sets of commonly used powertools and lease it for $xx/day. Etc. "Sharing economy" now means that you cover all the expenses of running a business and share the revenue with the platform that brought you customers. There's very little actual sharing, but the economy works as usual.
I guess my point is: sharing works without intermediaries and there may be no money exchange to take a cut, "sharing" with the intent to make a profit inevitably leads to professionalization and requires the "sharer" to operate a regular business.