Treason: Is It Bad?

I am researching an article on treason, which is the word of the month over at Trump HQ. But is it bad? The US consitution’s definition is bizarre and unintelligble. Russia have put it more eloquently. As stated on Wikipedia:-

Article 275 of the Criminal Code of Russia defines treason as “espionage, disclosure of state secrets, or any other assistance rendered to a foreign State, a foreign organization, or their representatives in hostile activities to the detriment of the external security of the Russian Federation, committed by a citizen of the Russian Federation.” The sentence is imprisonment for 12 to 20 years. It is not a capital offence, even though murder and some aggravated forms of attempted murder are (although Russia currently has a moratorium on the death penalty).

The British definition, which is even more bizarre than America’s, was written in Norman French in 1351.

Why are we still using a centuries-old anachronism to talk about present events?