And ironically the US planes got high altitude threats well under control while low flying aircraft and helicopters, drones and missiles are the most likely to slip the net of air supremacy fighters.
That's a 'yes and no' answer, largely because the environment has changed, and more specifically the
sensor environment changed. Take the Sgt. York, for example, had the revolutionary ability to pick up any aircraft from ground clutter that is
anything less than radar opaque. That sort of radar capability is in the F-35 and in any upgrades to the F-teen fighters' radar sets (please note that the Sgt York's designers managed this feat
with an F-16 radar set, they had some bugs to work out on the sensitivity and fire control). So, unless you're skimping out on upgrades and maintenance (like *cough* Russia *cough*), modern aircraft are going to pick helicopters, missiles, and drones out of the ground clutter.
Add the 'fun' that is AAA rounds like AHEAD and... well... it isn't going to be a good time to be in the air.