1- the universe is infinitely big. Which means there are infinite number of stars, solar systems... So that means the number of planets that are able to sustain life is Large to infinite. Why are we still questioning if we are alone in the universe?
Because we still don't know yet the entire number of variables which make our solar system and planetary conditions life-giving in the way that we understand it. The drake equation is actually extremely limited in what it factors in. There may be shells upon shells of planetoids and cometary bodies orbiting our solar system as far out as 2AU which provide protection. The approach of the Voyager space probe to the Kuiper Belt indicated that there was some kind of oppositional force slowing its velocity, perhaps a solar wind. There's also the possibility that physics work differently beyond the most outer reaches of our sun's gravitational pull.
There are other factors too... like how we have one moon, and how that moon is the result of a precise collision which fractured part of early earth off. Without that event, earth's gravity would be different, we'd have no tidal forces, etc. What if we had two moons? We can't even fully map the environmental conditions which shaped other species
on this planet, let alone the conditions which made the planet happen and made it work for us. We will never know all the variables, and I'm sure some degree of happenstance was there too.
I believe that other primitive life surely exists out there, such as bacteria and perhaps plant forms. High level sentient life is another story. There's this notion that humans are somehow important or some kind of pinnacle. There is zero evidence that our spontaneous development of a higher ordered brain with a complex mind is going to be something that keeps us alive for much longer into the future. We're assuming that we have evolutionary advantage in the cosmic sense, when maybe we don't. Maybe having this kind of mind is actually a problem? Everything we have achieved on this planet in the past 150 years is because of short term gains only. We don't even know if humans can safely live beyond Earth for very long to go travel to these supposed places.
I believe non-material lifeforms are far more likely, in non-physical dimensions. Complex, relatively sentient physical life like us must surely be a rarity.
2- if there wasn't a superior being/a creator, mater has no reason to exist. So there must be someone that created it.
To me this is a non-sequitur though many people view it as logical. Even
with a creator, matter might have no reason to exist. "Why" is something that humans do but nothing else does. The universe may have no beginning or end. It may have no reason for existing at all. At the highest level, nothing we do here matters. Our individual lives are less than a nanosecond of cosmic time and we are not really in control of anything. Nothing that ever happens is permanent or necessarily linear. The idea that A leads to B leads to C all the time is a egotistical expectation. The Earth could be obliterated tomorrow.
What I'm trying to say is that everything is empty of self. Nothing here has
anything to do with you. You're seeking meaning because you think you matter. Relativistically, for a short period, you do; but in the grand scheme you don't. It's not meant to denigrate or devalue you. In the present moment you have a place here, I suppose. The endless search for meaning is a product of our monkey minds. You don't see bacteria or mice or whales worrying about this stuff. It doesn't make us better than anything else because we choose to care about 'why'.
