I've been thinking about this for some days, and struggling a bit to decipher the words from the sentiment. It's easy to fall back on clichés when talking about this. Since I've mentioned that though, here's one of my favorites:
If you're not falling, you're not trying hard enough.
A little context - I am an avid rock climber. In fact have a secondary YouTube channel that I'm slowly filling up with shorts about climbing. I don't want to get off topic though, but I'll leave a link at the bottom of this post.
Having said that, as a climber, if you only ever climb what you can already climb, you'll certainly get stronger over time, but your movements will most likely not develop to include more advanced (and often awkward) body placements that allow you to push your limits more effectively. Falling, failure, is an essential part of the process.
In music, this comes in many forms: working on riffing, or figuring out the technique for that song that is just a little too high, or maybe sending out the demo tape (figuratively speaking) yet again, and facing another rejection. When we bite off just a little more than we can chew, we create an opportunity to work through the process, and find out how we will circumvent the problem.
The process, I would argue, is the real reward in all of this. Sure, it's lovely to get the gig, but the process continues long after that one show. Then it's on to the next one, and the next problem (too frequently referred to as a 'failure') that conceals a gift for us.
Here's that link I mentioned: