4- Some of these intelligent life-forms might develop advanced technology, and even interstellar travel.
5- Interstellar travel would take a long time, but as there are many sun-like stars that are billions of years older, there has been plenty of time for such travel to have occurred.
6- Given all this, why haven’t we met or seen any trace of aliens? Where is everybody?
–u/NiceHouseGoodTea
Fix the atmosphere? You are too stupid to converse with any further.