This opposed to closed off “products” that change at the whims of the company owning it.
There’s a lot of misconception about how the open source comes to be and very small part, still significant of course, of it was really created for the benefit of a community. There are exceptions, but dig the organisational culture and origins and you’ll see the pattern. Also, thousands of projects are made for the satisfaction of the author himself being highly intelligent and high on algorithmic dopamine.