The largest issue is failing to understand the difference between a commodity and a service, and how easy a substitute is to find.
Others vs uber(and uber like companies) are different
Uber solves an extremely hard problem that looks easy, it also has very few alternatives. The other services solve a problem that is less urgent, had many substitutes and is largely less valuable.
Uber provides transportation when and where it is needed. If you simply need (using the most well known detivative business) to borrow a skill saw from your neighbor for a tool sharing site you have many options. This project may be planned in advance, you may be able to purchase a used tool, and you may be able to borrow kne free.
The issue is how variable a service is. Uber can generate transportation for where and when you need it. However it may appear that the commodity is transportation, but that is the variable. Finding a user and providing them transportation from an unknown location, to an unknown location, immeadiately is hard. A ride from Logan Airport to south station is much different than a rake/hammer.
Each ride has a large amount of logistical constraints. Out toolsharing example has to solve all the same problems except a tool is always the same tool. A ride is never the same ride. It makes it much less valuable, and much easier to compete as there are often many substitutes and less expediency. Therefore coverage & on demand has a sup/demand musmatch, is prohibitively expensive and can only take a very small slice if value.