This question stemmed from comments under another Q&A where @Chocolate points out that「毎日学校に行ってきます」doesn't work but 「今から学校に行ってきます」is fine. But I am still not quite sure why it doesn't work? When people leave home for school or work every day there is a routine 「行ってらっしゃい」「行ってきます」 exchange. I'd like to know why we can say 「毎日電車で学校に行く」but not「毎日電車で学校に行ってくる」.
Why don't 「毎日」and「行ってくる」like each other?