Why do commercial planes not have ejector seats?
I could spend 20 minutes typing out an answer, as I have before to this same question. Go to the “search” box at the top of the page and type in “parachutes airlines”. You will get about 100 matches. That will save everyone a lot of time – you and me and anyone else who would rather not repeat the same answers they have given before. Read some of the answers to all of the other questions that are posted on this topic. There are some very lengthy and detailed answers, from a lot of people who know what they are talking about. That will tell you a lot about the reasons why ejection seats and parachutes are completely impractical on commercial aircraft. There are about 20 different, good reasons why it would never work. It is in no way as simple you you propose. Seriously – read the answers you will find as a result of the search – you will learn a lot.