Capable at what? Asking seriously.

You didn't ask me, but just off-hand I would say he's much better at mending fences than Trump. Trump tried to shred many of our alliances, allowing -for example- China to fill the void, talking about leaving NATO, antagonizing our European allies. Biden is fixing / has fixed all that. He's a MUCH better politician than Trump could hope to be. We need our allies, we need alliances, we need partnerships. It's in America's best interests. China was more than happy to try to become the dominant player in southeast Asia, and they are making in-roads in Cuba and Africa. That is bad for us.

I know "politician" has odious associations, but a skilled one can still get stuff done. And understands diplomacy. Joe wasn't my first choice ever, but if the alternative is Trump...slam-dunk vote for Joe. He also appointed relatively competent people into positions of authority, as opposed to Trump who appointed either his son-in-law, or yes-men.