Surprising there are not more solutions here. We have seen these style of drones for a number of years. I guess it’s a hard problem in general but I also wonder if part of it is simply the historically entrenched defense industry.
Part of it has to be owed to how tactically potent drone swarms are, as a means of asymmetric conflict. Even the best layered defensed are limited by magazine depth, whereas attack drones can be sent in theoretically unlimited waves.
In practice, this was seemingly validated by the 2002 Millennium Challenge controversy: https://en.wikipedia.org/wiki/Millennium_Challenge_2002#Exer...
Microwave/directed energy fixes this.
The solutions already exist and have been proven on the battlefield. Peacetime military forces are just slow to adapt, as there are no real incentives to adapt quickly.
Drones such as the Shahed are little more than cheap mediocre cruise missiles. Because they are cheap, the enemy can launch them in large numbers. You counter them by detecting them early and then using plenty of cheap mediocre anti-aircraft weapons. Mostly guns and interceptor drones (=cheap mediocre anti-aircraft missiles).