Can the orb ones not be beings?
There are clearly those type of UFOs that look more technical, but this orb ones do not really look like machines.
I am thinking of the flyers from Castaneda, that feed of our energy.
http://www.soul-guidance.com/houseofthesun/predators.html
When you watch the video from the Tether incident, you can see all this orbs, and they are pulsating and they look more like being alive, critters, that were attracted by the release of energy that the broken tether created.

I think we are too obsessed thinking of them as machines, (not a surprise, as we are machine minded) but who knows what other lifeforms there are that are residing in our black spots of perception. Just something to think about.

I had an encounter with two orbs, one next my window while and by coincidence, seeing this video, the exactly same one, suddenly an orb appeared in front of my window, the light was like a liquid light it reflected 3 or 4 types of colours, red, bright white, blue and a type of yellow. was amazing exciting and frightening as hell and because i went into panic mode it left. But it was a huge experience.

The second one was through my dedication in several encounters at night near my place. It always started with a feelling, a sensation in your heart that i should go out there to experience that kind of activity, it was like a training for me to learn how to put myself in a higher vibration in order to access and see with my eyes those realities where they operate. They are really all over the place. Had an encounter with one disc shaped object with blue lights all around i said goodbye and it flashes me with the lights like a response and disappears extremely quickly, other encounter was with several ufos's and i started after putting my self in that vibration be more in tune in communication, well at least i believe it was, started to have a kind of change of communication, and several visual perception communication, cannot confirm this part 100% as it could also all be my own imagination tricking me.
In one of the nights i tried contact with an orb again, but with no sucess, so i believed, moments later once again in front of my house saw another one disappear in front of me, it was like it started get smaller and smaller until it disappeard.

I believe and according to other studies, that the orbs are attract to places with huge electrical atmospheric activity but it could be also their doing, i believe also an orb is an expression of their Merkabba spinning in a higher frequency, it is also an expression of their dimensional energy projection, so we see it as orbs.
At least that my understanding.

I think there are numerous phenomenon, not one single thing, and so it makes it a bit more difficult to answer.

I think, firstly, there's clearly ET activity with actual machine craft.

But then, I also think there may well be inter-dimensional entities, as well as those just outside of our visual range - which may give us another two types.

The ET are limited by whatever UFO technology they are using suggesting that they are constrained by certain rules/Laws
which clearly shows that they most likely are just humans or human like just like us just far far more advanced
so they also were subjects created by the one GOD of the entire endless universe.
Let us never forget this .

Here's a german RV project investigating the creation of crop circles:

https://signallinie.info/die-entstehung-von-kornkreisen/

There seem to be many different creators, including humans, but also orbs. They even talked to one, respectively the consciousness associated with that orb, and perceived feelings of joy. This doesn't mean the orb is a living being itself, but it's definitly not just a machine. And it didn't come from space, which is also interesting.