Wood is a material which is limited in use in high-voltage transmission. Because of the limited height of available trees, the maximum height of wooden pylons is limited to approximately 30 m (98 ft). Wood is rarely used for lattice framework. Instead, they are used to build multi-pole structures, such as H-frame and K-frame structures. The voltages they carry are also limited, such as in other regions, where wood structures only carry voltages up to approximately 30 kV.

In countries such as Canada or the United States, wooden towers carry voltages up to 345 kV; these can be less costly than steel structures and take advantage of the surge voltage insulating properties of wood.[10] As of 2012, 345 kV lines on wood towers are still in use in the US and some are still being constructed on this technology.[16][17] Wood can also be used for temporary structures while constructing a permanent replacement.

From Wikipedia. Yeah wood is used and it actually has insulation properties.

You never answered my question about why it “obviously” can’t be done. You’re googling is terrible apparently, use wood and high voltage, lots of results.