Why does it need bold new design and innovation? More people (can afford to) fly every year, more safely, and with broadly more consistency than they ever have. The success of the commercial aviation industry as a whole is breathtaking.
To your argument of (paraphrase here) 'it is good enough why innovate'. I flat out reject that argument. Horse and buggy were good enough. The telegraph was good enough. We only needed 1 mb of memory because it was good enough. We are missing so much right now. We potentially could have small, efficient, point to point air taxi service for the average person, completely dismantling the massive, and horrible to deal with for people, hub and spoke system. Travel could get so much better and cheaper, but instead we have the 737 max. An incremental change on a decades old design because real innovation is lacking in the industry.
That's not my argument, you are putting words in my mouth. My argument is "you better have a good reason to argue the commercial air industry is stagnant because the industry's incremental progress over time has been incredible." Look at this chart: https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft
That's crazy!
The issue with your 737 MAX story is the trade-offs they made - oversized engine without massive recertification or requiring airport retrofits - worked. It is an absurdly successful product despite the early engineering failures. It is the best selling Boeing aircraft of all time and the second best selling commercial airline of all time (to the a320).
Innovation for the sake of innovation isn't worth anything, the current commercial airline stack is deeply optimized and delivers low cost, safe travel to hundreds of millions of people globally. What, exactly, would you like to see innovation on? What trade-offs are you willing to make?
I spent a few years in the commercial airline industry. They have a ton of problems, very few of them would be solved with a revolutionary plane design.