It can be used for basically anything, but most people with the power or influence to get it without violence can already do what they wanted to do with it. Like, Zelda has access in some games but she's already doing what she needs to do and is a princess, when the gorons are in trouble they either deal with it or someone fixes it so they don't need it, and so on. People outside these benevolent positions fight for it, which led to the shadow temple being full of bodies from civil war, and the triforce being sealed in the sacred realm and needing the ocarina of time and mastersword to be accessed. In skyward sword it was used to destroy demise, but then ghirahim timetraveled and Demise set his curse. So yeah basically it's only used for good reactively, as most positive things can be achieved in other ways and it's actively used for evil. On the brightside, the triforce of power is the only one that does anything useful, by magnifying your strength. And that's only sometimes.