I'd imagine it's access to capital and resources. I suspect many engineers/professionals (especially in eg consulting or manufacturing) would start their own business if they have the financial stability to do so.

A lot of market forces tend to "naturally" create monopolies/oligopolies. For eg if you're the biggest steel plant you can operate efficiently and keep moderate margins, beating any plants not as big (economies of scale). An independent guy (or even the entire team) can't just open a new steel plant shop down the road, even if the current one sucks.

That's basically the meme, right: You rail against corporations and yet you work for one. Curious.

Anyway in general, corporations are sticky. They save resources through scale and collaboration. Famously this is a problem for free market true believers because if you believe that the market is the most efficient mean of organizing people then you would expect firms to operate internally as free markets (or disappear). There is a whole body of work about it,

https://en.wikipedia.org/wiki/Theory_of_the_firm

In practice you can't just become your own boss and compete against firms.

Engineering and running a company are very different skill sets. Engineers are often not good at Marketing, networking, sales, ...

Even if you are good at those, for many companies, it's more about connections than about the ability to build stuff. So if you don't know the right people, it is very difficult to get a foothold.

I have AuDHD - there is no way I'm running my own company. I'm a good developer but I need someone else to have the idea and run the business and I can lead a small team to bring it about.

Given I'm now in my mid-50s, things are looking grim. And I'm not getting paid SV silly money. I'm not even getting paid US dollers.

Managing things often requires a different skillset, some want to avoid solving meatspace problems, some are not destined to be good at it.

Capital.

what?