Re: Did we have this problem with telegraph poles?
We are used to having long, thin, energy-carrying things burried around here.
There's a world of difference between burying a wee pipe for gas or oil, and burying an HT power line.
Overhead cables are insulated by the air around them, which also conducts away the heat they produce, neither is an issue for a gas pipe. See the National Grid information, which says:
To match overhead line thermal performance for a 400kV double circuit, as many as 12 separate cables in four separate trenches may be needed, resulting in a work area up to 65m wide. In addition, water cooling may be used
The heating losses can be reduced by increasing voltage and so reducing current (power loss being proportional to the square of the current) but then the cables are much thicker due to the need for more electrical insulation. Gas insulation is a possibility, which can help with cooling, but you're effectively burying a pipeline filled with a greenhouse gas (SF6), which has it's own environmental issues.
With AC distribution you get further capacitive losses, which can be reduced by using HVDC but that adds complexity and expense in the AC/DC converter stations.
And of course any future repairs or upgrades to capacity can mean digging the whole lot up again, not just stringing another wire.
There are very sound reasons why most long-distance power transmission is overhead, with only an occasional drop underground in the most sensitive areas.