i really suggest you to read the book, it will to answer your question fully. We live in a game theoretic (google game theory) landscape, in that regard you just cant hope that someone is gonna do something in your interest for no reason, u gotta undestand that you (as in people) dont need a leader you need a representative in our current governmental setup. u have to have them depend on you as much as possible, if u let your leaders/representatives or literally anyone who has power over you be independent and make decisions freely - you gonna be fucked in the ass. especially in our current world when we have so many people and they can outsource your job or make you obedient one way or another to their wants and needs. for them we're interchangeable with any sort of other worker and i hope u can see what it means for an average citizen. for you as a person from greece i would recommend to listen to a book called "Austerity: the history of a dangerous idea" by Mark Blyth, he's a professor at brown university, amazing book about the history of capitalism and what actually happened in 2007-2008. these 2 books are just amazing at their respective subjects and will change your perspective on politics and economics.
I just wanted to add when i reread your msg... It's not about personalities, people talk about Trump, Putin, Erdogan - it's a waste of time and energy, it's all about structures that govern the actual rules of our world, it's not about people per say, these leaders are only allowed to play by the rules of economics, politics, game theory. Even if you elect jesus christ as your president, it's not gonna make things amazing all of a sudden.