> A small team could perhaps release a game under an OSS license, but it wouldn’t be what we generally think of as open source development.

This is... definitely what I think of when I generally think of open source development? The vast majority of open source projects seem to be by one person. How many zero-star projects are there on GitHub? Half the libraries I use on a regular basis are authored by one person.

I think you are conflating contribution with direction. I'd argue most successful OSS projects have strong direction led by a small team. Postgres core. Python's BDFL, while it lasted. Even projects like Git have people like Junio, who are wonderful and knowledgeable and without which the project wouldn't even be remotely the same.

> These games had very specific artistic visions, and I’m not sure how you’d execute that.

There is no requirement for consensus-driven democratic decision making for a project, so I really don't get why you feel this way.

One of the first projects I contributed to was BZFlag, a game.

What about Colossal Cave Adventure? Rogue? Nethack? Hell I spent probably a few dozen hours playing Tux Racer since it's release.