First things first: nobody wants to be the leader except, well, leaders (and even then there might be some reluctance).
Secondly, everyone, and I mean pretty much everyone (unless they’re a completely self-defeating nihilistic anarchist), recognizes that someone needs to lead. Without a leader, not much gets done.
So that means that someone is left with the often thankless job of leading. An interesting side note here is that it’s not unusual for the job to be thrust upon them almost by default. When a role needs to be filled, the group will naturally turn to the one who seems to have the qualities needed to get the job done.
It’s not a job that most people would want. Failure or success will fall on the shoulders of the one who leads. There will be lots of unpleasantness to be dealt with, and many, many frustrations. Those being lead will constantly grumble and often question the decisions of the leader, even while privately thinking “thank god it’s not me.”
But for those who have a natural predilection for it, there can be an almost perverse pride in overcoming seemingly impossible obstacles and doing a job most wouldn’t (or couldn’t) do. Even in the face of hardship, they steadfastly look out for the safety of the ones they are leading, and never lose sight of the objective. The more you beat them down, the more determined they become. They pay a price, of course – but they accept their responsibility and forge ahead.
That’s what leaders do. Against all odds, sometimes reluctantly and always self-questioning, at the end of the day they serve the greater good for the group, because that’s who they are.
Inevitably someone must lead. Fate or circumstance will thrust someone into the position, and if they are a leader, they do the only thing their nature allows.