In terms of the US i think there are deeper problems to be fixed before really worrying about term length. A really obvious one that no one seems to want to tackle is that the sizes of political bodies in the us federal government (the house and the Supreme Court in particular) have been frozen for about 100 years while the population and diversity of the country have both exploded.

Get it so that a member of the house represents a reasonable number of people (and the body as a whole can return to actually being somewhat popularly elected - right now you almost have two senates really) and the court’s ideological balance can’t be completely u-turned by 2 people dying in as many years and then you can maybe fix some other stuff.