Drones are cheap. EW is even cheaper. The US has multiple C-UAS systems in use and even better ones in development. Some are just EW systems, some are cheapo gun based systems, and other are directed energy weapons. Missile based systems are the best but also the most expensive of the currently deployed solutions. The cheapest missile system is probably the APKWS that we've shipped to Ukraine. This uses a laser to guide the missile to the drone. But for countering FPV/Mavic type drones, even those are overkill. Just jam the entire area on the frequencies in use, and deny everyone drone use.
It's important not to draw too many conclusions from the Ukraine war. The combatants are fighting a much different fight on both sides than what the US would do.
EW is very much not magic, and both Russia and Ukraine absolutely do use it.
The problem with barrage jamming is that it's extremely locatable and your jammer just ends up getting blown up. The solution is to have many smaller jammers, but then range is decreased dramatically, and it can still be economical to just bomb them, possibly with an anti radiation munition (slapping such guidance on a drone is not expensive).
That said, the range is sufficiently small that it doesn't matter - cheap systems can just use visual odometry and inertial sensors and fly themselves the remaining 300 meters to the target. There are videos of Russian lancets operating exactly like this, flying high, locating a target, and then autonomously homing in as they get into jamming range.
The idea that neither Russia nor Ukraine tried just EW is quite ridiculous. It's well known that Russia had excellent EW, there was a report in the Texeira leaks that Ukraine could no longer use Excalibur guided shells because Russian long range jamming rendered them useless - the GPS jamming made them unable to arm, and that even US guided HIMARS missiles and JDAMs had to rely on inertial sensors for much of the trajectory with significantly reduced accuracy.
Yeah, our military says HIMARS are pretty much done due to the russian EW. By dragging this war, the US gave russians the opportunity to learn and battle test their solutions against HIMARS.
Excaliburs are on a much different level though. Word is, you don't need much EW at all. You merely have to give them a strong look and that's enough to drive it way off course.
Excalibur is highly effective when not being jammed by Pole-21 systems. It's just that Ukraine currently doesn't have enough systems to counter the GPS jamming. GMLRS faces the same issues. Both systems have inertial guidance in the face of jamming, but the accuracy drops off quite a bit. Just means you need to launch more GMLRS per target, or attack when jamming is off.
Never said EW was magic, nor that neither Ukraine or Russia was using it? If they weren't, the battlefield would be even more lethal. Russia has been a leader in EW for decades.
But it is the most cost-effective solution. Russia has been deploying vehicle mounted EW systems to jam drones (with some success), as well as jamming GPS. And the Ukrainians have been jamming as well. There's no wunderwaffe in any war, it's more a game of cat and mouse.
Just like APS is now becoming standard on tanks and AFVs, localized EW jammers targeting control frequencies of small drones will be the cost of having a real military. There's also been research into using APS against drones (this would require additional sensors).
And the JDAM/HIMARS jamming is a bit overrated. Even in inertial mode, JDAM has a 30m CEP, and HIMARS has a 60M CEP. Definitely not as good as with GPS, but still a serious issue for the Russians.
It's important not to draw too many conclusions from the Ukraine war. The combatants are fighting a much different fight on both sides than what the US would do.