Burying high voltage transmission cables is extremely expensive [1] and usually only done when there is no other choice (such as being in an urban environment, near airports and the likes) as the loss due to capacitance is far greater than on poles.

The exception to the "usually only" is, once again, our beloved "german redneck" government in Bavaria who insisted that the new North-South line Südlink got buried on Bavarian soil to quash local NIMBY resistance [2] - at the price of taking ages longer to build and costing ~8x the amount of pole-run lines.

[1] see page 64, https://www.amprion.net/Dokumente/Dialog/Downloads/Studien/E...

[2] https://www.sueddeutsche.de/bayern/energiewende-warum-erdkab...

I think the comment I replied to was referring to normal powerlines for households. Individual solar+batteries is not going to replace high voltage lines.