the biggest practical advantage to renewable energy is that we can produce it ourselves and become independent of crises that happen in another part of the world. for example the iran war.
for digital infrastructure, it’s the same. if facebook changes their policy to surveill all citizens in a new way, that creates a shock for everyone else. if we can self-host our services, then we become independent. so it’s like solar-panels in the back yard, but for digital infrastructure.
The efficacy of a system should be prioritised above its efficiency.
Pursuing efficiency exclusively, or even primarily, leads to excessive optimisation and brittle systems. Sustainability requires efficiency to be balanced with resilience, which requires redundancy.
Resources sitting idle is only wasteful if your goal is maximal extraction.