In my experience in silicon valley, people start with building something small/simple (but in a big market), get little drips of funding from investors as they show progress. If they fail at any point along the way, there's value in what they've created, and they exit for whatever they get. The later you exit, typically the further along you get, and the bigger the exit. That's why the diversity of outcomes in the valley are everything from zero to billions, and companies raise anywhere from zero to a dozen rounds of funding.
At any inflection point in the business, you have lots of options: you can sell, raise more money, raise more and cash out some shares, you can quit, you can make yourself chairman and have your cofoudner run it, you can do nothing and grow it organically, etc., etc.
Each one of the choices above are part of your arsenal of options at almost any point. The people who choose to raise tons of money, not cash out at all, and then who fail- well, they made a series of active decisions to do all of that. They're big boys.
My point is, when you're building a company you can make a lot of choices along the way, and it's not just setting out for a suicide run of either 1% of $100M or 10% of $10M. Choosing to raise outside financing is sort of like deciding whether or not you want a cofounder (or 2, or 3) - it just another form of business partner. You get less %, but hopefully they add to the business in a meaningful way that leaves you better off.