First i want to say sorry for my late reply, i took a break of a few weeks from here, also very recently a short time completely offline and i want to say thank you for your reply as well and for your "thank you" also

Also please be aware this is gonna be looooonggggg
I agree with you completely that the universe is truly infinite, when people tend to think of the universe being infinite they generally think of the field of stars, galaxies, nebulae and so on as never ending. as in if one were to fly in a ship and carry on they would never reach the end. But not many think of little and large way of looking at it. Just inside a tiny speck of dust is millions upon billions of life forms, what we are seeing really only "scratches the surface" as it is only currently the surface we are seeing, i bet that if we keep zooming our microscopes, our electron microscopes and contraptions not yet even invented it would be never ending.
If you think of it the large way, this whole universe could be in a petri dish, sometimes as something is so small it cannot be seen, something could be so big that we cannot perceive it.
Think of the point of view of a microbe, if we were shrunk that small and we were seeing another human looking at us, we would not see "him/her" at all, we would only see a very very very small part of the human looking at us, we might not even recognize it as a human at all, one for us being very very tiny and only seeing our "corner" of it, and for another we would not recognize it as a human if we were to view it due to our ways of life being so different. we would attempt to name this being by our own system and not perceive it as we perceive ourselves, as a human being, or even a being at all. Maybe we are only looking at a small part of the whole, and yet as we cannot perceive it all we would not be able to perceive the human being looking at us due to being microbe tiny.
maybe we are looking at a being and not knowing it, or rather our small part of it

I also agree with you that the stereotypical "grey" form may also be our future form through evolution or through artificial means. I was adding to this by thinking maybe this "grey" form is not exclusive to our own evolutionary path, who is to say that other races in the universe might not have already taken or are going to take this path? It has been said that there are different types of "greys" maybe those different types are all different races that have undertaken this form.
you might wonder why this form is so widespread, well just as the stars themselves become widespread and seen throughout the universe so do many forms, the humanoid, reptilian, furry, octupi, elemental ( including the living rocks on earth), spirit forms are widespread so is the "grey" form. Also lets not forget the microorganisms, who might be different but are microorganisms nonetheless, just as you can have different types of reptilian, and humans.
But this is only a very very small part of the spectrum of life forms out there.