In the animal world it means getting a potential mate.
What about humans ?
Why do we have the desire to win ?
I mean humans are animals too.
Winning what?
I guess you could say that winning is like money: it has value because we say it does.
If you’re competing at something, odds are good you spent a fair amount of time working on the skill you’re using. Winning means you have honed that skill, and it’s progress to be proud of.
It means getting a potential mate.
That doesn’t explain video game competitions.
:flees:
Getting a mate, yes, but also survival. If there are limited resources (and after all, what resources aren’t limited?), there will be competition for those resources just to stay alive.
Winning shows that you are better than everyone. That you have power. That you have control.
Winning is feedback that validates whatever preparations you went through (or whatever you innately are) that enabled you to achieve that victory. It’s not subjective (or possibly insincere) praise from your parents or your boss - it’s real, objective praise from the universe.
I think it’s not merely winning in a contest between human competitors that pleases us, either. It could be any kind of challenge we choose to take on that tests our abilities and affords us an opportunity to demonstrate, if only to ourselves, that we’re capable human beings. Climbing Everest, building a grandfather clock from scratch, smoking the perfect pork shoulder, carving the perfect turn on a motorcycle, whatever.
Bottom line, achievement feels good.
I think it’s more related to mating and resource distribution. If you “win”, you’re the person who “won”, meaning you get a greater share of the food/pointy rocks/whatever, or getting the choice place in the cave. And/or you’re going to be perceived as more attractive as a result because you’re in that position, versus the person who lost, and gets a lesser share. And to some degree, you’re the person calling the shots, as opposed to being told what to do.
It’s the same reason everyone wants to be rich; after a certain point of income, it’s about status, not creature comfort, and what does status buy you? Hotter women/men, and that ability to call the shots, rather than be told what to do.
I think that this is either innate, or ingrained in human cultures to the point where people engage in competitions for the sake of winning/losing, even when there’s no actual status or resources to be gained.
Depending on the answer to that, winning might NOT be important. Sometimes, we do the activity for reasons other than to win.
Because losing sucks?
Heavy answers. 
With the skills that we learn on our own I guess there is that sense of accomplishment that is strictly personal. A personal victory that no one else needs to know about .
Building clocks, learning to play guitar, smoking that perfect pork shoulder etc.
I guess the winner gets the spoils be it a mate, food or a cozier place to sleep.
If the concept of winning was not there do you think the world would have been a better place ?
I am reminded of the story of a south Indian king who while watching his first soccer match felt so bad for the players chasing after one ball, ordered balls for all the players.
Would a lack of desire to win be considered a lack of ambition ?
I am uncertain how the concept of winning could be removed. Children run foot races even if no one tells them to and shortly there after are competing to climb the highest rock or jump the highest or whatever else.
I guess if we lived in a world where every person got everything they desired including attention from the people they want attention from then winning would go away and I guess that having your every want fulfilled would be better than our current world. Sure sounds boring though.
I think it’s a very broad question. Depending on what kind of thing we’re talking about, the answer may be: to impress others or obtain social standing (like animals trying to get a mate), basically play behaviors (similar to other hunting animals*) or just their own motivation (humans can have arbitrary interests and motivations, and how that happens is an even broader topic than “winning”).
* …depending on the nature of the game. As well as simple one-on-one games like wrestling or tag, humans also play team-based games and entirely strategic games. But these may also have an instinctive component, as working in teams and making good strategies (and not being outsmarted by others) will have been quite important to our ancestors.
Generally speaking, there are fewer “rewards” than people pursuing them. That could be a job, a mate, a desirable project at work, a property you want to live in, a limited spot in an organization such as a team, etc. Unless everything is to be selected by random drawing, there is usually some form of competition involved. It could be some form of meritocracy, bidding war, or just first come first served.