You have done the pattern again of invoking an infinity with hand waving. 10,000 drones is an immense amount of money. If each of those drones cost $2000, a very reasonable price for a military attack drone, that is $20 million you just dropped on a single attack.

$20 million is a serious amount of money, you can buy a whole lot of counter UAS systems for that amount of money, and those systems aren't a single use, disposable tool like the assault drones you dumped all of your money into.

A shahed costs closer to ~$30,000 than $2000 so this point holds even more true for longer range flying bombs.