I did this for several years, and it didn't give me anything near VP-at-Google skills, maybe "VP-at-so-so-company" skills. I was in charge of development, systems administration / DevOps, SEO (got multiple things to the top of Google), some management (of non-technical freelancers, because I was the only full-time technical person), and a variety of other "fill in the holes" jobs. This was after multiple stints at other small companies (but not 5 full-time people small.)

I got some things out of of it, no question, but absolutely nothing compared to what I would have gotten at a high-quality company that had reasonable hours, plenty of capital, very ambitious people (no one who worked there is anywhere near technology now - most are 9-5 or non-technical consultants), interesting technology, etc. The most important thing I got was "be incredibly careful about who you work for and what promises you choose to believe", but saying to people "don't be naive / foolish" is easier to say than it is to evaluate the intentions and capabilities of founders / companies. The second most important thing would be the ability to say "I've been through the wringer before."

The quality of companies varies wildly, and the wrong environment will do very little for you. Some wind up at ones near the bottom of the quality pile and having the ability to recognize that you're at one isn't a given.