Yes, mars lost its atmosphere millions/billions of years ago due to low gravity and meteor impact heat plumes.
Crater chains are natural as explained by gravitational tidal effect on a fragmented meteor, many of the chains have varying distances from the craters and the craters have varying size, not things one would expect of an accurate and precise weapon. Carpet bombing is not something we would expect from an alien technology that would be more advanced then ours. No evidence of alien cities can be found that are discernable form natural rock formations, No evidence of any form has yet been found that is discernable from natural formations.
The day you find actual indisputable proof of your theories, is the day you will go from being a kook to world hero, but until then you’re kook, so leave us now as we will not believe you (until you bring us indisputable proof) and spending further time here is a waste of yours and our time. Go back and find your indisputable proof and then you can come back and say “I told you so” and be victorious.