Space is an option..... Only for the US. Not so much for the rest of us. There really is only one company that can pull off the line of global coverage the Pentagon wants. The same one that is also building a global comms network for the Pentagon (which could (likely is) carry other sensors).
For everybody else? There's a spectrum. We absolutely can and will use space based radar for coverage over certain AOIs. But it would still take us two decades to get to the capability the Americans want to get to globally in one. In that time, and to enable expeditionary ops beyond, we need air breathers.
I don't think the USAF is wrong either on survivability. The PLAAF designed the J-20 with exceptionally long range. The PL-21 missile has exceptionally long range for a BVRAAM. The size of their sixth Gen fighters implies long range. None of this is optimized to take American fighters head on over Taiwan. Instead they are designed to fly unpredictable routes and kill tankers and emitters in the rear.
Even in a Latvia scenario, I question the survivability of manned AEWC that is any closer than say 200 km from the leading edge of friendlies. We have seen Russians kill a Ukrainian fighter at 190km using an R-37M. Similar to Chinese PL-15.
The question becomes. At what point in the development cycle does a single large manned AEWC become obsolete because the standoff required eats up too much detection range? To me the eventual approach has to be some kind of quarterback approach. Either an airborne or ground based command node using a network of drones with sensors that can get closer and are less painful to lose. I would hope Globaleye and the like are being designed to transition to that quarterback role.
The Globaleye, for us, is at best, relevant through the 2030s. We'll definitely need to have a conversation on survivability beyond that. Or at least at that point, the conversation will become public.....
What about all levels of counter measures. Which I do not think Ukraine has access to.
It was not that many years ago when the allies went in and spoofed the Iraqi Air defense system with multiple levels of counter measures active and passive.
Our (allies) EW/ Surveillance aircraft are being fitted with both offense and defensive weapon systems. Along with their "sophisticated counter measure suits"
Right now we put all our eggs into one basket relying on the F35 to be end all package deal. It was to replace AWACS, it was to replace other counter intelligence/ measures aircraft in a all in one package that could swoop in with its data fusion process and control up to 4 autonomous wingman aircraft while directing multiple other non stealth aircraft to destroy and hinder the enemy.
We need a mixture of aircraft, That is why I was a fan of the F18 Growler ECM capable suit. Was it perfect over all no. But the overall package was good enough for what we would require as we transition into 5, 5+ -7 gen systems.
Now we have a pretty good chance of building a good overall system of Stealthy Aircraft (F35), surveillance aircraft (P8, Global Eye, CE-145C, and the NASP Dash 8,) along with the general duty (Gryphen). Of note the Gryphen can be fitted with a pretty good Counter measure, jamming, foiling suite. Is it the best, maybe maybe not. But it has proven systems in one package that we can utilize for the foreseeable future.
If ball actually gets roiling we may have a well balance fleet across the board with all our aircraft.
Honestly if the F35 program in its fullness could actually get to a point where it worked fully integrated with all its promises then we would be set for the next 5 years

instead we are still hoping for the best radar and hoping for all that sensor fusion to work as proposed/ promised.
I honestly believe once we get rolling with what has been actually committed to and have the actual physical systems in our hands we will use the equipment in ways people did not think of. It really is the Canadian way. Those little tweaks will allow us to be at the top. We just need build the road to drive first.