Because the Linux of today is not the product of a company or person with a focused vision but a conglomerate of devs from various foundations or corporations, each with their own agenda. A lot of things may seem "obvious" but depending who's at the helm, other stuff gets prioritized.
I remember, way back when, in college, when I would try to listen to music while my machine was torrenting a movie on the same HDD, the playback of the song would get totally borked because the queuing scheme of the linux I/O scheduler at that time could not cope with this(it was tuned for server operations) even though both Windows and MacOS could handle this scenario without a sweat since like forever.
IIRC BFQ scheduler finally addressed this later but I'm not 100% sure on this info.
I remember, way back when, in college, when I would try to listen to music while my machine was torrenting a movie on the same HDD, the playback of the song would get totally borked because the queuing scheme of the linux I/O scheduler at that time could not cope with this(it was tuned for server operations) even though both Windows and MacOS could handle this scenario without a sweat since like forever.
IIRC BFQ scheduler finally addressed this later but I'm not 100% sure on this info.