Why materialists are predominantly materialists

[Jesster]

The reason to believe in more than the material world is that there is a material world?

I'm not sure why you say "more than."  First, we need a reason to believe in the material world AT ALL.  Then we can start the work of deciding whether there's more than it.

Believing in the material world is the starting point. If you don't start by assuming that, we can't go anywhere at all. Since I personally observe that on some level, I'm going to go ahead and leave that as a given. Anything beyond the material world doesn't even have that much to work with yet. That's where I will need more evidence.

I'm not going to get into the holographic universe hypothesis with you if that's where you are going.