Boeing will never build a 757 replacement. I would argue that the 787 is the last new aircraft program Boeing will ever do. The MAX budget was a bit less than $ 3 Billion . It was supposed to be the cash cow that would fund the 777X and NMA, however the impairment costs for the MAX debacle are nearing $ 20 Billion. The Max will never be profitable at a unit level even if Boeing builds 5000 of them and 787 program is a sucking chest wound being covered by more and more field dressings. The reality is that Boeing is locked in a crisis short term program management decision making loop that still prioritizes stock valuation over anything else. I see no sign of the C suite vision that gets them out of the downward spiral, if recovery is even still possible.
Boeing will blunder along for the next 10 years or so bleeding money and market share with a revolving cast of C suite MBA bean counters fixated on cost metrics until it hits the end of the road. We have seen this movie before and its name was McDonald Douglas Aircraft. The "businessmen" supplanted the engineers and a once proud company faded into irrelevance on the face of serial crashes caused by poor engineering (DC10/MD11 ) and lack of product investment (DC9/MD 80 series) in order to achieve short term stock market gains. That is assuming there is not another MAX crash directly caused by an engineering or production issue, in which case it is over for Boeing.
This will be a sad ending to what once was a world leader in commercial aircraft ...