That takes some faith that being an unselfish team player will in fact get you somewhere.

From a mgmt perspective, assuming a good manager, it does.

If your team/org doesn't approach it that way, the solution is find a high performing team that does approach it that way, not become toxic yourself. 10/10 high performance, long term successful teams approach things this way (source: this study, and people who have experienced this approach luckily).