An oil without a flavor. Olive oil is an example of a not neutral oil since it imparts a flavor to the dish.
Corn, vegetable, soybean, canola and peanut are good examples. No one would drizzle a little corn oil on a plate to dip bread in. :)
They also can tolerate higher temperatures, so you can use them in cooking a bit easier.
The "point" is that it's a tasty beverage.
Why on earth would you measure the quality of a beverage by how diluted the solids are, or how much filler gets strained out?
"Milk is just watered down cheese! It's 87% water! What's the point of it?"
Coffee hardly has any coffee in it, you throw away most of the bean.
Don't even get me started on broth.
The fat content is equal to or lower than the fat content of typical dairy based creamers, which is also where the sugar content comes from. A mild quantity of fat is required for the creamer to have a good mouth feel and have a degree of "coating" effect. The gums help keep the fat in suspension since I lack a homogenizer like they use on milk, as well as increasing the viscosity in a way that's imparted by protein in milk.
If you want to you can just eat the result without filtering. It's called oatmeal. It's still watered down though, so I might recommend toasting them and having a nice dry oat bar to go with your puck of dehydrated milk.
In general, I'd recommend against putting any sort of creamer in your black coffee. It tends to make it no longer black coffee.
I don't personally find issue with any of the emulsifies doing anything to coffee I don't like, but if you're exploring there are plenty of others. I've had good luck with konjac in a blend with guar, xanthan, and methylcellulose, but two of those are less likely to be in the baking aisle at the store. The more you use the smaller the proportional quantity you need, since they have a synergistic effect. Less than a gram total combined weight of the four previous ones makes a consistency like heavy cream. Great for ice cream base.