That may be, and I would hope that such would be the case. But beyond sheer material needs, I am of the opinion that if a lifeform reaches sufficient intelligence to where it can destroy itself as a species, it must also, as a race, master itself in terms of its animal origins. View it as a test of sorts, and most races fail, as humanity very well may, animal nature and its difficulties being what it is. That would make for a bit of quiet... although I would also agree with you that whatever methods of communication such races use, it is probably designed to be undetectable.
Those races that do manage to survive themselves would behave in a benign fashion, neither helping or hindering, allowing other species to follow their own course. I would like to think that creatures of a sufficiently advanced nature would not need for anything, nor be disposed to take what they need by force if that wasn't the case.
There's one more bit you mentioned about "cracking the physics puzzle" to allow interstellar transport. Something I note about all these various UFO sightings, which actually date back thousands of years, is that the basic geometry of these things hasn't changed in all that time. As you note, just look at how our own technologies have reshaped themselves over and over again within just the last 100 years. These things haven't change in over 2,000 years. Whatever they're using here, it appears to have hit the bottom of physics.
These things haven't change in over 2,000 years. Whatever they're using here, it appears to have hit the bottom of physics.
That is quite interesting, isn't it? I suppose that there's a "bottom" to every technology. A point at which there isn't any further need for improvement or change.
Take for instance, the simple bowl. That's a design that's difficult to improve on, nor is there any practical reason to. A brick is a brick is a brick, unless it's a block, which is simply a variation on that timeless building unit. I suppose we could name thousands of human inventions that have hit their developmental "bottom".
Your observation would tend to argue that at least some of our visitors have reached a plateau in their technological advancement. It would seem to me, in that case, that scientific curiosity would have to be their chief interest in us.
There's also the political to be considered. Perhaps the Sol system is disputed territory. Perhaps it's even traded hands a few times.
Wouldn't it be interesting to find that our politics are little more than primitive tribal disputes, and that the politics that really matters is going on light years away from here.