I had some pretty clear failures when I was starting out, but they didn't cost much money beyond web hosting, a domain name, and some wasted time. Sure, you can always worry about some existential risk, such as causing real harm you're liable for. But that's starting to sound like an excuse not to take action.

My main point is that it is actually possible start a business with almost no risk and almost no capital. Not that you'll succeed. And if you don't that's OK.

Failure is an option, and if you're smart, it's an option you can easily recover from.

Honestly, I think I learned half of this attitude from playing competitive video games in the late 90s. You just keep trying stuff. If it doesn't work, you can do another round. (Gah -- I'm in awe of how much free time I used to have.)