We’re looking for (relatively) high powered radio signals. Regardless of how alien critters evolve, they’re going to have the same constraints on their radio technology as we do.
It is possible they’d have some reason for pouring a tonne of energy into loud radio broadcasts, but if they are using radio for communications (as our SETI searches assume), then they will have lots of incentives to stop screaming into the void. At which point, our searches will not find them.
We’re looking for (relatively) high powered radio signals. Regardless of how alien critters evolve, they’re going to have the same constraints on their radio technology as we do.
It is possible they’d have some reason for pouring a tonne of energy into loud radio broadcasts, but if they are using radio for communications (as our SETI searches assume), then they will have lots of incentives to stop screaming into the void. At which point, our searches will not find them.