Academically, Linux is obsolete. You couldn't publish a paper on most of it; it wouldn't be original. Economically, commercially and socially, it isn't.
Toasters are also obsolete, academically. You couldn't publish a paper about toasters, yet millions of people put bread into toasters every morning. Toasters are not obsolete commercially, economically or socially. The average kid born today will know what a toaster is by the time they are two, even if they don't have one at home.
My father is a retired physics professor. I tried debating him once about an aqueduct in a town near us that was built in the early XX century.
His view is that it was moronic because communicating vessels had already been known for centuries.
I tried arguing that maybe they didn't have the materials (pipes), or maybe dealing with obstructions would have been difficult, etc. After all, this was a remote location at that time.
I think that the person who built it probably didn't know about communicating vessels but that it is also true that the aqueduct was the best solution for the time and place.
Anyway, debating academics about practical considerations is hard.
Toasters are also obsolete, academically. You couldn't publish a paper about toasters, yet millions of people put bread into toasters every morning. Toasters are not obsolete commercially, economically or socially. The average kid born today will know what a toaster is by the time they are two, even if they don't have one at home.