Supersonic flight is an old technology. The innovation would be to create a commercial flight without a sonic boom.
So far people I have spoken to about this have been pessimistic because of the high level of investment required.
Yes, and there has been recent discussion of supersonic flights that reduce or redirect the boom. In a time when very few people are flying anywhere, and the cost to operate a supersonic jet making the user market extremely small, your idea doesn't address a need that a significant number of people have. Unless you have a proven design, I don't see much hope for this idea. Investors aren't keen to fund any kind of experiment. They want sure things.