I thought cheaper and slower moving counters would be used such as helicopters, a10s or propellor powered planes with guns (rather than with an expensive missile, I did not know if APKWS).

I guess, missiles shot from f15s are still cheaper than an interceptor missiles.

A-10 or propellor powered planes are more cost efficiteve but it looks like the US doesn't have enough of them and had to use much more expensive but numerous F-16 and F-35 e.t.c.

The US was not prepeared to counter drones and even after 4 years of the war in Ukraine still doesn't take economic aspect of drone warfare seriously continuing to behave like cost doesn't matter.