Just because the universe has a cause doesn’t mean that cause is God or the Christian God.

Yes, that's definitely true, this argument does not prove that monotheism is true, much less the Christian God. All it says, and all it intends to say, is that the universe was caused by something. To find out what that something is, we'll have to do some more reasoning or bring in more evidence. As far as evidence goes, other arguments like the fine-tuning argument and the moral argument tell us that this cause seems to be interested in the existence or life and that life's behavior, which would coincide with the claims of monotheism. And course to examine whether it's the Christian God, we would need to look at Christian particulars, which are outside of the scope of our discussion here.

But even if we stick with this argument, we can get somewhere on our own steam. Like the video pointed out, the cause of the universe must have been spaceless, timeless, immaterial, uncaused, and immensely powerful. Not only is this suspiciously similar to the traditional conception of God, it might be asked, what other possible candidates are there?

What else might have these properties? The only thing that might fit the bill are abstract objects, like numbers, that don't depend on spacetime reality. But the problem is that they are abstract can't cause anything; it's hard to imagine "42" creating everything (even if it is the meaning of life in The Hitchhiker's Guide to the Galaxy).

So given the untenability of abstract objects, God is in fact the most reasonable explanation.