Interceptors being more expensive is a big problem. The only solution I can think of is ground-based lasers, which cost a few dollars per shot. If they can be protected.

Other than that, you either need the X-factor of intelligence and air superiority, which bypasses the problem by taking out bottlenecks like TELs and supply chains. Or, have more industrial production. If you have neither, you're in trouble.

A mostly independent thing countries can do is have better home-front resiliency, which is a kind of defense in depth against suicide attacks. Taiwan needs this. Get everyone a bomb shelter.