It's an immense legacy improvement for LeBron James. Even though 3-4 isn't a huge difference from 2-5, there are several factors that are huge.
Bringing a championship to Cleveland.
Winning with 2 different franchises.
Third finals MVP.
Beating the record setting Warriors (who everyone was handing their 2nd title to)
Coming back from down 3-1 (first team ever to do that in the finals)
At 31 years old, he is tied with Jordan's 3 titles and 3 MVP's at the same age.
This was a big one, no doubt.