Curate, connect, and discover
Dumbledore was clever, cunning, and magically powerful. If he wanted real power, he could have quite quickly brought the wizarding world to its knees. Actually, he feared power and deliberately limited himself from it and tried not to get involved in the most political decisions because he knew he had a visionary side that could make him start deciding people's fates "for the greater good." He knew he could make mistakes. That's why all his positions were not really about power but were more like representative and guarantor roles, where there were many other decision-makers, and his power could be limited by others — from headmaster (from which he was disgracefully kicked out) to the position in the useless magical version of the UN.
Dumbledore didn't seek power, he feared it. That's why he avoided making some decisions and increasing his power even when he could and should have done so (like taking the post of Minister).
At first Harry thinks Dumbledore is almost like a god, but then he realizes that Dumbledore actually has no real power, makes mistakes, and is just an ordinary person with his own flaws, who has been fighting his inner demons all his life and can't forgive himself for a mistake he made in his youth.
Dumbledore is actually a deeply traumatised character who is often afraid to make decisions and avoids doing things because he believes his actions sometimes don't lead to good outcomes. He avoids action even when it's really needed, doing the bare minimum.
He is very distant, closed off, and I think quite an unhappy person. I can almost see the pain Dumbledore went through with the whole Harry situation, but it was a difficult decision that only he could make, and he actually hates himself for it, which is why he distances himself from Harry as much as possible (I don't think it's the right decision. I see it as Dumbledore's weakness.) Dumbledore's death isn't a sad event for him, it's the release he had been waiting for a long time.
This is such a simple idea that I really don't understand how people see him as a character who fought Voldemort just to keep his kinda pathetic power.