Interesting side effect is that this reliance on cables introduces a dependency on copper which already is in short supply and which can be mined only in specific regions.

So it re-introduces some geo-political dependencies. Not in the way fossil fuels or unranium do, because a copper cable won't "burn up" to produce the energy, but they do need some upkeep.

Another dependency this introduces is the network itself. A failure in specific regions could lead to massive blackouts (Like recently in spain/portugal) or could even become political pressure instruments like currently the russian-natural-gas-pipelines in Europe are