Is it necessary to cook porridge (oatmeal)?

It is possible to just eat porridge (oats) after soaking in water for a couple minutes.

However, cooking it makes it creamier and softer.

I'm interested in knowing if cooking the oats actually changes them in some way (besides the heat), and if there is technically a difference between cooking vs. not cooking. (e.g. is it the case that if I leave it to soak for a longer period without heating, it could achieve the same softness?)