The Second Law of Thermodynamics says that 100% efficiency isn't achievable, because energy gets lost due to the way it spreads out, and getting it back itself is a use of energy, which costs more than it pays.
A good example is Maxwell's Demon, a pin-dancing "thought experiment" from the good old days when people knew what
thermo- meant. A stove loses heat, can't be helped, so you have to fuel it. If it didn't lose heat, reduce in caloric content over time as it were, then it ought to stay hot forever and you wouldn't need to fuel it. What use it would be, I don't know, we use them to heat things, but let that pass for a moment. Can it really not be helped?
Let's postulate a demon, there in the stove, who chases the little hot air molecules for us, and grabs them, and drags them back into the stove, so the heat doesn't get lost. In a case like this, do we have 100% efficiency? No, because the demon is doing work, work requires energy, and energy is what he is supposedly saving for us, we have to fuel him somehow. So now instead of wood we have to burn sinners or something. Still fuel, energy still lost.
Only applies to information, particularly genetic information, in the sense that "a lot of work is done." Even here, all it means is that there has to be a fuel source. There is, the sun, both directly and through secondary manifestations like hot lava, radioactivity, chemical reactions, and the endless spinning of Rudolf Clausius in his grave. Nothing to do with emergent systems like evolution and intelligence being unable to develop on their own, they result from the inevitable increase in complexity among large stochastic systems, and represent increasing entropy overall, not decreasing, not ever.
* note that Maxwell actually used this fiend for a somewhat more complex purpose, as a gatekeeper with a magic flashlight; he still fails to prevent entropy however, no matter how he does the work