Indeed it's not as wide as 2 monitors, but you can split workspace into 2 applications and that's still quite comfortable. E.g. when working on web-development you might have VS-code and browser opened at the same time.
I know what you mean, I have used 34" and 38" UWs and they feel large enough. But a 25" UW is tiny and actually has 12.59% less space [1] than a single 24". And most run at just 2560x1080.
[1] http://www.displaywars.com/24-inch-16x10-vs-25-inch-21x9