People are only willing to sacrifice for the collective if they think it's their "team", they are joined with it in a non-transactional way.

Sometimes it's obvious that it's another team, e.g. when you're collaborating with employees of other companies.

But in a large enough company, often the "same team" mindset isn't the same. There can be legitimately big differences in goals and expectations across different parts of a very large company!