The SETI project has not yielded any evidence of alien life

Question: Do aliens exist?
Position‹4 of 4: Detection or contact with an alien life form is not possible
Argument‹2 of 2: The SETI project has not yielded any evidence of alien life

The Search for Extra-Terrestrial Intelligence has been operating for long without giving any evidence

The argument

The SETI project looks for alien life by listening to radio waves from space and discriminate from natural emission (form stars, galaxies,..) and signals generated by an intelligence. So far the research did not provide any results proving that detecting a communication is highly unlikely,

Premises

[P1]The SETI project searches for alien life by listening for radio signals from space and distinguishing those generated by an intelligence from natural emissions like stars and galaxies. [P2] Decades of this research have yielded no results, suggesting that detecting such a communication is highly unlikely. [C] Therefore SETI's lack of any evidence indicates that detection or contact with an alien life form is not possible.

Counter-arguments

Looking for radio communication might be a limiting factor since it assumes aliens communicate in a method similar to ours. Charles Stuart Bowyer states that method might be ineffective: it also requires that communication is directed towards earth or Solar System with a high-energy beam. Hearing a radio leakage similar to our radio and TV transmission is extremely unlikely.

Rejecting the premises

The "Fermi paradox" states that Earth should have already been visited by alien or their probes.