I have high tension wire running across my property. 5 years ago they replaced all of it. None of the wire was insulated. Uninsulated high voltage transfer wire is the norm not the exception.
It’s illegal to have uninsulated high voltage lines per national electrical distribution codes.
If they were uninsulated the 70,000 volt lines would be arcing off the towers that support them and non stop fires.
All power lines require insulation period.