If you work in a siloed, fractured business, it's likely your products and services will be too. The same is true at a team level. A product is only as good as the relationships you have with your teammates. If you have a dysfunctional, egotistical team - it will show in the work.
We're not able to restructure an organisation or pick a dream team to work with. So we must take the Stoic view. What can we control? There is only one answer: our own thoughts and actions.
Every day, we make lots of small decisions. You may find yourself getting into a heated argument. You could fight to prove everyone wrong. Or you could concede and say "you're probably right". Another day, you are praised for some work. You could lap it up, or you could decide to shine a light on others instead. Like karma, the sum total of these decisions creates a positive or negative culture in your team. You get to decide.
If people were plants, the relationship would be the soil. Consistent watering and nurturing is what makes the plant grow. Treat every decision you make as a chance to water the soil. And remember, your ego is not an effective watering can.