I'm a UI developer who specializes in designing and developing tooling for SASS products.
My last company was in ad tech, and our UI was for setting up ad campaigns. A big campaign consisted of 1 campaign, 30 line items, 900 tactics, and 2,000 creative assets. We offered managed service, meaning the account managers were in house and I could observe them work.
When you're working with quantities like this, every UI choice is hit by a multiplier equivalent to the campaign size.
My favorite was a request for table sorting. Makes sense, users want to sort 2,000 creative assets, and sorting is something every UI should have However, asking why they're sorting revealed that they were trying to identify "orphan creatives", assets which had no assigned tactic.
They'd open each creative in a new tab, and assign it a tactic. Also not a big deal, until you multiply that action by 2,000.
They'd also need to spot check the assets to ensure they weren't accidentally assigned to incorrect tactics, a feature that no one thought to request.
Ultimately, the request from our AMs and Product Management was: "Please add sorting to tables." What I ended up building took over a week, and took the shape of a nested folder browser that allowed bulk actions on multiple entries. All because of a sort request that was hiding an issue.
So what was the impact? We had lots of large campaigns, which could take up to two stressful days to set up. The new tool minimized errors and took at most an hour (thanks to some smart generator tools I added later on). We had 5 full time technical account managers who went from extremely stressed during Christmas to fairly calm. Errors decreased, resulting in better campaigns.
One thing remained, and that was the muscle memory senior account managers had developed for setting things up incrementally. I learned that when you build a tool people use for hours a day, every small task is important. The motions embed themselves in a user's brain. The mistakes or inefficiencies of a UI, seemingly insignificant during development, can become someone else's rote action, stressor, and even source of unhappiness.
I don't affect the global economy, but questioning a sort feature made five of my coworkers happier.