MMU itself is an F16 replacement and export. TuAF historically does not like single-engine fighters. That was the reason all retired generals kept writing about their desire for a twin-engine configuration.
F16 has pretty much been all we had all along. I would say people have grown to love them. See how many forum members have the F16 in their nick names.
Power projection to where and why? The USA can do it because they have a military budget almost equal to our GDP. The power project is something that even China, with its massive economy and population, can not do.
Thinking of today alone is short sighted, think about 15 years into the future. The US has $65k GDP and their costs are on that basis. We can do stuff at a fraction of the cost, so does China.
There are proposals. Reasons for Concorde to failure are still there. It was banned from almost everywhere because of the sonic boom, which is something we can not dodge. Supersonic flights, by their nature, face much harder drag and therefore needs extra fuel. Civil aviation calculates almost every liter of fuel for survival now, and we are saying let's go supersonic passenger aircraft.
When cars go electric it will be only some of the ships and planes that will use petrol, 15 years down the road.
It was the Antonov who begged for help to rebuild An-225. Also, we should not call asking for partnership as begging.
When you are not choosing exactly the design you are needing you are taking charity where you can not chose how much. Let's just says it in reverse "if you are not choosing you are begging" (beggars are not choosers).
Then, you have to put fuel and avionics. And surprise, you get something with the size of an aircraft with the price of an aircraft. So what is the point here?
Not necessarily: planes need to land and that's why they have to be able to slow down and land slowly while a missile does not need to land so there is no need for landing gear and large wings for slow flight. Lots of planes weight can be taken out and replaced by fuel or warheads. Even if you have planes they can be hunted down easier than a missile.
Just like Airbus had every ingredient to make A-380. Almost went bankrupt, saved by the EU.
The USA imposed inflight phone and computer use ban to flights from the Emirates which put the nail on the A380's coffin. It was too risky and facing competition from the USA. A smaller plane like 80 Passenger or whatever the MMU engines can support will be easier to make. The USA wants to fly troops with reusable SpaceX rockets and what do you want to do for a similar use, buy American rockets?
Planes fly subsonic like at mach 0.94 over land and at supersonic mach 1.7 over seas.