1. Sample size of three people (one per monitor arrangement).
2. A 25" 21:9 ultrawide is not comparable with 2x 24" 16:10 screens. You'd need something like a 44" ultrawide to get the same screen width (omitting bezels)
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.