The aspect to me, that doesn't involve the traditional alien race destroys humanity, is an idea I heard in an astrophysics podcast. It is still pretty terrifying although I guess more sad.
An advanced aliens visited the earth hundreds, thousands, or even millions of years ago, extracted all of the rare compound that allows for their ability to have such an advanced society capable of traveling such distances and just left. We are purposefully being ignored since it is known to the galaxy/universe that we have no way of effectively reaching or communicating with other advanced civilizations.
All of the useful material was extracted so no advanced alien civilizations even have a reason to come and visit.
What's more common is just pure aggression or selfishness
That said, if there were an intelligence at the scale of a planet (just a thought experiment, maybe like the "Planetary AC" in The Last Question by Isaac Asimov: https://www.multivax.com/last_question.html), i doubt they'd see us as much more than mold, which we'd find on a loaf of bread ourselves.
On the other hand, ants are interesting, just for curiosity. We can certainly amuse and entertain, just like ants do, and we can afford leaving alone their nests, just because they don't really bother us.
But if we mean stepping on a single ant, not all the ants, then it's certainly possible aliens could kill a few humans inadvertently.
Having said that intelligence and curiosity go hand in hand, hard to imagine them not being somewhat interested in the specs.
Just create big hermetic container, and put there minerals, bacteria and fungi. Heck, people even do it at home with big sealed glass bottles.
No need to bring living biome. Just bring spores, seeds, sperm and eggs.
But this is not the main point. It's still extremely expensive. Imagine that world GDP needs to be taken for few years just to build single ship. Who would agree to that in democratic society?
See: lions, tigers, bears, wolves, bobcats, mountain lions, etc. anywhere that humans have a meaningful presence.
Your argument vastly underestimates size of the Space and the amount of goods in it.
I firmly believe that the third option will take place: "no one needs to bother". Why bother destroying some little tiny pale blue dot, if your sky is literally filled with them and you can't even count them?
We're so focused and enclosed our minds on our precious Earth, that we laughably think is so big and valuable.
There is a kinship bond within members of the same species, although it isn't universal. As John Donne said, "Any man's death diminishes me, because I am involved in mankind; and therefore never send to know for whom the bell tolls; it tolls for thee." We're human and the Sentinelese are human, and even though we're not genociding them (mostly, I think, because they have nothing worth killing over otherwise they would have been dead a long time ago,) we're still genociding plenty of other fellow humans. We even avoid killing animals to extinction because humans share and suffer the consequences of living in a complex ecosystem with other beings. But we also cut the fins off of sharks for soup and throw them back into the water to drown.
But none of those connections would exist between aliens and humans. We're not one of them, nor do we share the same biome, so our deaths might well be entirely void of meaning or consequence for them. In a Dark Forest scenario, there's little to no advantage to contact or cooperation with an alien species, and every possible advantage in sending a GRB to fry anything that so much as looks like life before it has a chance to evolve into a threat.
>But none of those connections would exist between aliens and humans.
That's exactly why humans are more worth killing than aliens: we have conflict of interests with humans but not with aliens.
>We're not one of them, nor do we share the same biome, so our deaths might well be entirely void of meaning or consequence for them.
If the Sentinelese disappear, the biome will likely become only more rich.
at the very least it would be a strong reason to go build the biggest space shield and hold it between this planet and earth while we figure out the rest. Anything short of that would be incredibly naive.
So the thinking is less that we're a threat to them now (if they can get here, we certainly are not), but some intelligent beings may look at how we have treated one another over the last few centuries/millennia and decide that they don't want us (or any self-replicating machines we happen to plop out) roaming/colonizing/populating/enslaving/murdering/reeducating the galaxy.
Looking back historically, many of the European powers of the 1500s-1800s were literally millennia ahead of the people they colonised in terms of technological prowess.
In spite of this, indigenous ideas, beliefs and culture still had an influence on the Europeans (and if it weren't for the attitudes of the time that influence would be much greater and we'd be all the better for it).
I wouldn't be surprised if Aliens with advanced technology discovering Earth found the same thing.
I don't think this is true. India was colonized, and it had very comparable technology - perhaps 50 or 100 years behind. There are cases of very primative people being colonised of course, but often the capabilities of other civilisations are minimised in our history - for example north american natives are seen as hunter gatherers whereas there was extensive farming and land exploitation in many places in the USA - along with pottery and settled living.
We have hands-on experience as a species with technologically primitive societies being discovered by technologically advanced societies and going on to influence language and philosophy.
Given this, I don't think it's a given that an advanced alien race would look at us as not worth their time.
Unless, of course, we turn out to be a delicious delicacy
Two possibilities exist: either aliens can reach us or they cannot. If they cannot, it's sad. If they can, they are already so advanced that they need nothing from a small blue speck of dust in the vast Space that we call Earth.