> how does one/how do we end up feeling like this? And how can you work toward not feeling this way?
It's a broad question because there are many underlying causes.
Some people have unrealistically high expectations for what can be accomplished. As engineers, it's easy for us to visualize the big picture of how things would look when they're finished, but forget all of the details and difficulties that must be overcome along the way.
Some people spread themselves too thin across too many projects, such that none of them see any rapid progress. I know a lot of brilliant people who could accomplish great things if they'd just make the choice to stop all of their side projects, learn to say "no" to new requests, and pick one initiative to be their main focus.
Some people think they want to deliver results and finish things, but when it comes down to it they actually prefer the craft part of the process rather than the finishing part. They'd rather write and re-write the same code 20 times until they've perfected it and generalized it for every possible situation, rather than ship an imperfect version that gets things done.
And some people genuinely aren't working diligently or effectively, usually because they haven't yet learned how. I see this a lot in younger people I've mentored: They aren't getting much work done, but they also can't figure out where all of their time is going every day. In one case, I worked with someone who couldn't figure out why they were so unproductive and exhausted every day until they enabled a time tracker on their phone and discovered that they were losing over 8 hours every day to playing on their phone screen. The worst part was that they weren't really enjoying it, either. They just got into the habit of wasting time on social media and it spiraled out of control. Needless to say, getting a handle on that was life-changing in terms of what they could accomplish everyone else in their lives.