There's some survivorship bias here. You often just end up looking like an idiot or being really bad at something. I agree that embarrassment shouldn't be a barrier but one should be aware of the flip side. "Putting yourself out there" mostly results in humiliation and rejection. Focusing on being thick skinned and resilient is maybe more important than imagining you just need to get over embarrassment.

If you try new things, you may go bankrupt, get laughed at or be humiliated in a much worse way, be regularly rejected or talked down to, etc. It's not just about being brave for a minute. And in the end you might never make it.