I don’t really think so. The level of brutality world wars pretty much always necessitate is the reason they are short. You cannot sacrifice that amount of people forever.
Vietnam was different for sure, but it just isn’t the same situation as a world war where multiple modernized military forces are going at it with the most cutting edge technology and tactics available. I think another reason world wars don’t last as long is because they are wars that are much harder to extract profit out of too. You have to sink an insane amount of resources into it at the cost of pretty much all other economic activity.