A better world

Izuku lives in a chaotic and imperfect world, all kinds of bad things happen all the time, and with this power he saw the opportunity to fix the world.

But first he needed to test, he took a few deep breaths to make sure he didn't stutter.

"I, from now on, have full control over One for All and am able to use it 100% without consequences"

After that he tried to use it and...

He managed! His glowing arm was easily filled with power without consequences, Izuku continued testing One for All for a while.

And then he decided he would use it to improve the world.

"Education in empathy and justice be widely available, encouraging better personal choices."

"Let the resources for resolving conflicts peacefully be strengthened, maintaining the need for heroes"

That's it, and with that he apparently helped to solve problems in the world and make it more peaceful without interfering with people's free will.