I'm from a small European country with no notable natural resources nor other economic influence. Legally, the government has quite a lot of authority, but its power, measured by how it can specifically influence events, pales in comparison to the power of certain larger countries that can actually affect more.
Facebook is the primary source of news for many, many people and can greatly influence their view by choosing to bury, or prominently display, stories promoting a particular stance. It's likely that Facebook could flip the outcome of a close election in a heavily FB-using country if it wanted to. Facebook controls several of the most popular services people use to directly message one another, and it could choose not to deliver messages containing certain words or links. Facebook can (through the FB Pixel) build a highly accurate history of web browsing for most online users, something major governments can also do through NSA, GCHQ or Spetssvyaz, but smaller governments don't have that capability.
Facebook can't launch nukes or assassinate anyone anywhere with a drone strike, but if you look past the several national leaders who truly stand out in terms of power, I'd say you would find Facebook in the next rank.
Well, it depends how you measure.
Joe Biden has the power to start wars, to pardon people for US crimes, to have anyone disappeared and tortured indefinitely - but he doesn't have the power to create a database listing all American citizens, let alone the citizens of foreign countries.
It's my understanding that the NSA did just that under Bush and Obama though. I might have only one side of the story, but in all countries where some part of the state surveillance apparatus was exposed, the law seems to be carefully crafted to look like it forbids mass surveillance while actually allowing the executive to implement it.
To lead effectively, you need both. It’s rare that leaders have both. Biden does not have the soft power to do such a thing.
Soft power vs hard power also is a part of every relationship, even with your grandma or friend.
Let's add a header to Facebook's homepage insulting some country's leader, and see how fast they get beaten into removing it by a court.
The guy heads a communication company. This is nothing close to the power of a national government. A lone US senator might have less influence, but the president of any country has more authority than MZ, except maybe over Facebook, depending on how protective that country's law is.