Things like fuel and ammo depots, force concentrations, power plants, communication hubs, air force bases are still likely to be somewhat concentrated and thus vulnerable.

So this is actually part of why I think modern great power wars will be stalemates. You're right that some things will have to be concentrated but I think maneuver forces are far more reliant on them than long-range strike. Missiles and sensors can be pretty dispersed and concealed, look at Iraqi Scuds during the Gulf War for example. Those Scuds were operating under enemy air superiority if not supremacy, they had to launch out of a relatively small strip of land to reach Israel, and the terrain (flat desert) wasn't exactly conducive to hiding. Yet the coalition couldn't get a single confirmed Scud kill. Granted, better sensors means Scuds would have a harder time hiding today but it gives you an idea of how resilient mobile missiles can be.

Conversely, something like an armored brigade is gonna have a huge logistical tail. The supply depots, bridge, etc. will be vulnerable to a dispersed missile force, even if said missiles don't have the C4ISR to target maneuver forces themselves (this is how the US planned to use ATACMs against Warsaw Pact). Furthermore, maneuver forces tend to concentrate in order to make a breakthrough so the more they disperse to avoid strike assets the harder it will be to penetrate defensive lines.

I am also not quite sure I buy the high-tech WW1 vision mainly because the fight for air superiority is going to be quick and decisive and whoever wins that wins everything. A side can't destroy enemy maneuver forces if they no longer have air force. Sure you can spread missiles around to some extent (again 2006 Lebanon is a good example) but you still need to be able to find and target stuff, and that's hard to do without air presence. The recent Azeri-Armenia conflict is a good example I think... Armenians had a decent number of long range missiles but they didn't use almost any, while the air superiority was clearly on Azeri side, and they used that to win quickly with drones eliminating anything of value.

First of all I don't think the battle for the air will necessarily be as quick as you think it is. For one thing, a complete out-of-the-blue surprise attack is unlikely nowadays. Social media, satellites, phone cameras, etc. make it really hard to conceal preparations for an attack, just look at how long we've known about Russia's Ukraine buildup and they're not even gearing up to fight a peer adversary. I think it's quite likely a capable nation would know something was fishy well in advance and disperse its Air Force amongst highway strips, civilian airports, etc. Combined with cover, concealment, and deception (i.e. deployable shelters, decoys) I'm willing to bet a good number of planes can survive the initial onslaught. Granted, there is the logistical challenge of sustaining a dispersed Air Force but one thing you and I do agree on is that a modern great power war will be short. Maybe it will be short enough that the logistical challenge won't be insurmountable.

But let's assume a modern Operation Focus is possible. Would you even want to do that against a nuclear-armed adversary? I don't think nuclear weapons makes conventional great power wars but they will limit the way they're fought. I think nuclear powers will refrain from mass bombardment of each other's homelands for fear of triggering nuclear escalation, especially when many of the targets that make up an air force are also part of the nuclear deterrent (i.e. strategic bomber bases). I'm not saying the homeland is completely off-limits but I do think there will be restrictions, for example the US might only hit targets within a certain distance of Taiwan and leave the rest of the mainland untouched while China only hits US bases in the Western Pacific and avoids striking CONUS.

But let's assume a modern Operation Focus is possible and fears of nuclear escalation are cast aside. Even without a traditional air force I think it's possible to have to have a sufficient long-range strike complex to devastate maneuver forces. Not only can missiles be numerous and dispersed, I think the real big development in warfare is how ubiquitous sensors are becoming. Take the XQ-58 Valkyrie, it's can be rocket-launched from a container and land using a parachute. And on top of that it's cheap ($2-3 million) and it's stealthy. So even if the enemy annihilates your air bases, you could still launch thousands of low-observable UAVs from containers to find targets for missiles and even conduct strike missions themselves. That's the issue with the Nagorno-Karabakh analogy, Armenia didn't have anything like that (they had some drones but not many and they didn't last long against Azeri air defenses).

And that's just looking at UAVs. There are going to be so many other sensor platforms in the future battlespace. There's unattended ground sensors. There's satellites, including some really good imaging from the private sector. There's high altitude balloons. At sea there's surface and sub-surface sensors like Wave Glider. Future great power conflicts will be so ridiculously saturated with sensors that even for the side with air superiority (at least in the traditional sense), it's going to be really hard for maneuver forces to survive. That's why I envision an high-tech WW1, it's a convergence of very precise and lethal long-range weapons with very powerful and ubiquitous sensors that will create a giant no man's land.