This is often the opposite of the truth. That is, teams are much more often formally-owning software, but "owning" in the sense of actually being responsible and feeling responsible for its functioning, well-being, and strive towards polish and realization of potential - more often than not, it's one or a few individuals. If it's a large software system, a lot of people have to put in their work as well, but still.

I am occasionally in a situation where I feel more "ownership" towards a software project I have no formal responsibility for than I believe the formal owners do, and find the, to be poor stewards of that software. Not that I have the time to take over for them, but I have the motivation, and it pains me to see them mistreat it and mar it with unworthy merges.

PS - I am not speaking as a supposed "10x engineer".