Are we alone in the universe? My natural inclination is to say no, because everything in this universe comes in multiples, whether it be galaxy clusters, galaxies, stars and planets. The only singular things found so far in the universe are our habitable world and the universe itself. Now apart from the wastage of unused real estate, the universe has gone through a lot of trouble to create one singular habitable world in all its vastness. Is our world really just some toy wrapped in a ridiculous amount of packaging? If the conditions are right for us in our peripheral position within the galaxy, then surely somewhere out there is another form of life. What would happen if the human race disappeared in such a singular universe? Would another life form arise to take our place to fill the vacuum, as it were? Is this why we are finding so many new worlds and proto star systems, so that the universe is primed in the event of our premature or maybe even timely demise?
We know that nature abhors a vacuum and demonstrates this by filling up our universe with more energy, seemingly from nowhere. If the universe is constantly refueling' itself with particles and using energy to create stars, some with planets and ours with life, then life in some form seems to be a key component of our universe. Interstellar space is teeming with organic chemical matter floating through space, not alive as far as we know- but the very fact that organic matter is present in the vacuum of space speaks volumes for the universe's ability to produce such material. So the universe has all the key elements to produce life: A star's energy (and elements), suitable planet/moons, organic material and sustenance (whether comet water or chemical diets). It may be rare that they all come together, but it is not impossible.
Drake's equation basically boils down to the fact that there at least between one and millions of other civilisations out there. Our galaxy is vast and the universe is unimaginably vast. The chances of us hearing from another civilisation would be very remote. That explains the Fermi Paradox; we will not hear from another civilisation because they are so far away or are living/have lived at different times to us. Also consider Olber's paradox and why space is black and not lit up with all that star light. The universe is expanding and as it does the energy from stars is diluted, thus light cannot illuminate the entire universe. Now if light cannot get everywhere even at the speed of light, then how can us slow-paced civilisations hope to. Taken together Drake's equation is not totally positive nor Fermi's paradox entirely negative. They reinforce each other. Olber's paradox is neutral in that it also reiterates the vastness of space, but unlike the other two factors is a natural occurrence, rather than a man-made inference. So we have three key factors in determining the prospects of other life in the universe, which as with the above paragraph on materials for life, do not rule out the possibility of other life, just that we would be incredibly far away from another civilisation, even with light and radio signals.
I am not an advocate of the anthropic principle, but there may be a relationship between the universe's energy production and humankind. Just as we need oxygen, nitrogen, argon, etc., and the trace elements in our atmosphere to live, the universe could need its essential nutrients' to breed galaxies, stars, planet and life; after all, these dimensional particles and forces form the basics of all the elements and us. So we are here because the universe gets the right diet' of energy and is at an age to allow life to form. So whether we are alone or not, I do think that we are here at a privileged time of the universe, just as we are on the earth, because we could not be here at any other point in time due to the prevailing conditions. As above, so below; there is symmetry between us and the universe.
Are there extraterrestrials watching us now, benignly or ready to invade, from another planet, time or dimension? Who knows? Whenever or however they come, at least we will be comforted in knowing that we are not alone and that life somewhere will continue.