It may be a slight cause for concern if we find extinct life on Mars, but for it to be too much of a worry, you have to make quite a lot of assumptions. There are plenty of other explanations for the Fermi paradox that don't include a great filter, and this argument only applies if the life we found was dead rather than possibly still present microbiological life. And it's also assuming the life here and on Mars wasn't seeded from the same place, but Earth was the only hospitable planet.
My view is that it's likely/possible the universe is has quite a lot of life. However, since all evidence suggests the universe had a beginning, between abiogenesis, evolution, and the universe/galaxy/planet being in a state hospitable to life, it might always take a very long time to get the state we're in now, just as it did on this planet. It's quite possible that there are billions of planets with life in some stage of evolution, but few of them are significantly more advanced than our planet's life. Even if there are a smaller number of super-advanced civilisations, they may only have been broadcasting for a few hundred thousand years, and we may not be in range of that, or pointing our antennae at the right place to pick up the very weak signals. Even if they have discovered FTL travel, it would conceivably still take an extremely long time for them to visit every planet in the universe. Even if they have visited Earth in our historically documented timeline, they may not have been interested enough in what they saw to stop by and have a chat. Worse, if they have discovered FTL, they're probably not using radio broadcasts any more.
But that doesn't mean that life is uncommon, or even that there isn't some intergalactic federation of civilisations, just that any given civilisation being significant enough to notice or be noticed happens rarely. I would be far more worried about extra-terrestrials being hostile than non-existent (see Stephen Hawking's views on the matter).
Really, most of these sort of arguments feel quite similar to a bunch of humans sitting around a hundred thousand years ago, discussing with their tribe that they are probably the only humans on the planet, since no other more advanced cultures have communicated with them yet. Even though they haven't discovered any efficient means of transport to actually explore the Earth yet...
My view is that it's likely/possible the universe is has quite a lot of life. However, since all evidence suggests the universe had a beginning, between abiogenesis, evolution, and the universe/galaxy/planet being in a state hospitable to life, it might always take a very long time to get the state we're in now, just as it did on this planet. It's quite possible that there are billions of planets with life in some stage of evolution, but few of them are significantly more advanced than our planet's life. Even if there are a smaller number of super-advanced civilisations, they may only have been broadcasting for a few hundred thousand years, and we may not be in range of that, or pointing our antennae at the right place to pick up the very weak signals. Even if they have discovered FTL travel, it would conceivably still take an extremely long time for them to visit every planet in the universe. Even if they have visited Earth in our historically documented timeline, they may not have been interested enough in what they saw to stop by and have a chat. Worse, if they have discovered FTL, they're probably not using radio broadcasts any more.
But that doesn't mean that life is uncommon, or even that there isn't some intergalactic federation of civilisations, just that any given civilisation being significant enough to notice or be noticed happens rarely. I would be far more worried about extra-terrestrials being hostile than non-existent (see Stephen Hawking's views on the matter).
Really, most of these sort of arguments feel quite similar to a bunch of humans sitting around a hundred thousand years ago, discussing with their tribe that they are probably the only humans on the planet, since no other more advanced cultures have communicated with them yet. Even though they haven't discovered any efficient means of transport to actually explore the Earth yet...