They took over, but there’s still an argument for spy planes; satellites arrive on their own schedule in predictable orbits. This makes it very hard to get timely photographs, and it makes them easier to defend against. A spy plane could get in and out of a trouble spot within an hour, all before the enemy can hide the nukes or whatever.
A modern spy plane however would have to be faster than the SR-71, which I don’t believe would be safe against modern SAMs.
Based on the totally amateur knowledge level of someone that once spent a few hours researching stealth satellites (MISTY, etc), there's obviously a demand within the NRO for satellites that can be launched into a known orbit, with published two line elements, and then go stealthy and change their orbit into something which cannot be predicted by enemy nation-state ground forces.
I don't believe anything worthwhile about current capabilities has been declassified, it's all conjecture by people looking at the X-37 and similar systems.
A modern spy plane however would have to be faster than the SR-71, which I don’t believe would be safe against modern SAMs.