Am I missing something here?
Yes, two things.
The first thing is that you are using your own definitions and not the ones applied by labor law. There are six guidelines by Department of Labor. (Integral to business, permanency of relationship, worker's investment in equipment and facilities, nature and degree of control by principal, worker's opportunity of profit/loss, and skill/training necessary. While your brief lists are interesting, they don't match what the government actually uses.
The second thing you are missing is the definition of contractors. This is about the legally defined "independent contractor" or 1099'er, that are one type of contractor who is effectively a person operating as a business. There are other types of jobs that people refer to as contractors, such as short term employment (w2 with a time limit), or cases where employees of one company are brought in to work with another company's employees. Their decision is only about the 1099 style of contracting, which Uber uses.
Going through each of the government requirements as they apply to Uber and your Ebay seller example:
Integral test. Uber's core business is connecting people for rides and moving funds between accounts. Drivers provide rides using the service, but they aren't integral to the business of connecting people (although they are necessary to implement the task). Ebay sellers similarly use the service, but aren't integral in providing the service. MOSTLY NEUTRAL, slight bias toward employee.
Permanency test. Some Uber drivers meet this, others don't. Those who infrequently pick up riders, those who are on for an hour or two during the day, they're not really permanent. The ones who have used Uber to replace their income, or drive for many hours each day, they're much more permanent. Most ebay sellers are extremely transitory, having items up for under a week, or using it as a store front for goods that are constantly rotated. WEAK FAIL, some people biased towards employee, others biased toward 1099'er, so maybe some people should be reclassified.
Investment test. Uber has some investment through insurance and their guarantees, but leaves most of the cost to the individual. They've got a weak investment. Ebay has nothing invested in the sellers. WEAK FAIL, the long list of guarantees and insurance they offer to their drivers pushes toward employee.
Nature and degree of control test. Uber has a high amount of control, coordinating all the details of rides,establishing fares, and causing the drivers to be redistributed based on their algorithms, and requirements about the cleanliness and maintenance of the vehicle, but they also have weak control in other areas by not dictating work hours and a few other details. Ebay has zero control. STRONG FAIL, Uber's heavy control over what drivers do pushes strongly toward employee.
Opportunity of P/L test. Uber sets the fare cost, and takes a cut, the driver gets no options. There is no opportunity for additional profit or loss. Nothing they do personally can modify their results, get more business, get better rates, or otherwise modify the opportunity of profit and loss. For the ebay example, Ebay sellers can operate under whatever terms they choose, including running full brick-and-mortar stores, which many sellers start and operate as. STRONG FAIL, these "independent contractor" Uber drivers cannot operate as a business independently.
Level of skill/business acumen test. Uber drivers are hired for being able to drive. They cannot really market themselves independently, take good advantage of business insights, leverage their own personal strengths, modify their business based on any personal skills or talents. Nothing they do personally can modify their products or results. Strong contrast with Ebay where sellers have a large degree of control over what they do and how they do it, what they sell, how it is presented, and other factors of skill and business acumen. STRONG FAIL, these "independent contractors" cannot operate independently, leverage skills, or add any effective flair.
When it comes to tax status and employment status, I'm pretty sure the commission got this one right, or at least, right for the common case. It may not fit very well for those who only run the app a few hours each month, those small percentage of drivers might be better classified as 1099 independent contractors. But those driving more than around ten hours each week probably fit better under the employee definition, and those driving more than twenty per week strongly fit the definitions of employee.