A an example of rent collecting would be if he used his wealth to lobby for a law requiring all start-ups to have a license which an organization he controlled granted (and charged for).
If you truly don't think he is contributing to wealth creation, I can only surmise that you really don't understand the job he performs and the wealth created by people who are good at that particular job.
Angel investing and venture capital are jobs that are also prone to the Peter Principle. What makes them different than many other jobs, especially angel investing, is that the person has promoted themselves to their own level of incompetence. Just because some (maybe many) angel investors are incompetent and don't contribute to wealth creation does not mean that none do.
His essay focused on one particular lever, technology. His original lever was technology. Now he uses other levers, economic capital, social capital and experience to create wealth. Extracting value from economic capital alone is rent seeking. This is what banks do with loans. Providing economic capital with advise on how to most intelligently make the most of the capital goes beyond mere rent seeking and enters the realm of wealth creating activities.
He's providing incredible value/wealth to the startups he advises and invests in. I'd also argue that his essays are a great deal of wealth given to the world.
A an example of rent collecting would be if he used his wealth to lobby for a law requiring all start-ups to have a license which an organization he controlled granted (and charged for).