Well there are serial entrepreneurs that rapidly make companies with inflated value and sell them off quickly for big returns, and then there are the Elon type that are in part philanthropists lol. Those walls that you mentioned, especially technical, is when a guy like Elon will have to back off and be replaced by a much more qualified professional that is in that field.
Getting a company off the ground is completely different than the maturity stage. Once the sales pitches aren't needed anymore you need actual/consistent talent to continue executing long term. Again, this is when a guy like Elon takes a step back.
If you want an example of this, just look at AMD. Jerry Sanders aggressively got AMD off the ground and into relevance, but he was also the same person that almost destroyed the company from mismanagement in a time where AMD actually had market leadership. He was way too focused on the rapid growth of the company rather than their actual products.
You can also view this in terms of what is valuable to a company- and this changes depending on what stage of growth that the company is in. When a company is first starting it gets most of its value from the branding/concept/sales pitch. Then, over time that value transitions into the actual product/service that the company provides. Once that transition is complete an Entrepreneur/salesman is not providing nearly as much value to the company anymore, the people designing and creating the products/services are. The talent pool changes.
Which is a shame, I'd love some AMD branded headphones and coffee mugs lol