It’s very complex and involves issues of race, religion, democracy, corruption, economics, etc. But in another way, it’s not complex: Bolivia is sitting on massive untapped lithium mines. Someone is going to get rich from that and whether it’s the people of Bolivia or oligarchs is why coups are tempting:
I don’t know who is backing the current coup, obviously, but I suspect few corporations or Western governments would be upset if a right wing party seizes power (again) despite losing the last several recent elections.