Obviously, it is not known exactly whether there is life on the exoplanets. Importantly, we do not have enough observational results to show this. There may be life as we know it or may not. But from a philosophical point of view, I think,

a conscious will is necessary in order for something to construct a regular ecological system in any where. Also, it is not possible to explain such a regular structure by incidental movements or formations.

How can you affirm that life exists only on Earth? Do you have any proof of that? Proving that life doesn't exist elsewhere is physically impossible since you should explore all the planets in our universe...

Is it a question or a statement ? We just do not have a proof as yet, but the universe is so unimaginable large and variable - and consisting from the same matter under the same physical laws, that the matter evolution to the life MUST exist elsewhere. No natural science, only theological reason may limit the life occurence to Earth.

Life evolves according to the environment (adapt to survive). On Earth we have conditions that are best suited for us, we evolved according to those suitable conditions, we would obviously not survive without such environment that suits us the best. Elsewhere life will exist according to that environment. Not necessary that it has to be oxygen rich environment. It can be sulphur rich environment, may be methane rich environment, hydrogen rich environment or even radioactive environment where radiotrophic fungi can survive. One thing is for sure, we are not alone, when we look at the infinite realm of the Universe there are probably trillions of galaxies or even more, the Universe was obviously not created for life to exist only on Earth. We are limited by technology since travelling from Earth to another planet within our home galaxy to see if life exists there or not will take thousands of years or maybe more. We as humans are trying our best to find life on Mars. Other promising destinations include Jupiter's moon Europa.

We have a big universe. And we are not sure that there is no life on other planets. Perhaps the peoples on other planets/stars will think that why life is only here. Still there is a lot of work required to explore the universe. The stars and planets that we know have not the suitable condition of lives. That's why.....

This is the impression that almost any primitive civilisation will arrive at. To understand why it is necessary to know a little about dark matter and the opportunities for life after the stars expire. The first genuinely scientific explanation for the lack of incoming radio signals was published in recent years:

Article A cosmological hypothesis potentially resolving the mystery ...

Dear Jayaram,

This question was made for many people even here in RG in different forms. The reasonable answer is to assume that there are many places in our Universe where life exists and the main problem is how to contact them

http://www.iaragroup.org/_OLD/seti/pdf_IARA/cocconi.pdf

and also nowadays there are many different results

https://www.astrobio.net/news-exclusive/?/article504.html

Drake equation has allowed to calculate the number of civilizations in our galaxy Milky Way which could be extended to others in simple form.

Ah, the work of Morrison and Cocconi, and the Drake equation. Together they answer almost any question people might have on this topic. Then we have the presence of technologically advanced megalithic structures dotted all over the world, erected in the mists of time at carefully chosen latitudes communicating important information concerning physics, astronomy and mathematics, yet seeking no contact in return. How proud the academic community must be of all its accomplishments in these fields.

https://www.youtube.com/watch?v=VDPd5wOaBOU

First, define what you mean by "life". If such things as reproducability are included, I think "life" can and must be found throughout the universe. We need to expand our horizons.