I am writing this in hopes that search engines indexes this and saves potential buyers from this mistake.
If you have Asus ProArt PA278QV or any WQHD (native 2560x1440) and thinking of using it as MacBook M1 external display YOU WILL EXPERIENCE TERRIBLE, BLURRY FONTS WHICH MIGHT IMPAIR YOUR VISION AFTER A FEW WEEKS OF USE BECAUSE HIDPI FONTS ONLY AVAILABLE ON 4K MONITORS.
AND I AM NOT JOKING ABOUT EYE STRAIN, NEVER EXPERIENCED SUCH FATIGUE IN MY LIFE BEFORE.
This is by far one of the biggest bottlenecks caused by tech I've experienced in my life (13 years as PC user on all kind of garbage tech in the past). To give you perspective of how terrible this is: I got LG monitor from 2005 with max resolution of 1280x1024. Running Windows XP it renders notably clearer fonts. Go figure. The old monitor even has pigeon **** on it. And still looks better.
The Asus PA278QV I have works flawlessly on Windows 10 machine. Even with the same cable, which came from the original box. Such a simple task is however unachievable in the latest macOS Big Sur.