Repeating isn't as easy or automatic as people are making it out to be. This century, there are only 4 teams and 4 star tandems who have repeat championships:
Durant and Curry
LeBron and Wade
Kobe and Gasol
Kobe and Shaq
You can start to list the great tandems who have never won a title or only one 1. Tatum and Brown have 1 title. That is pretty good. 2 in a row is really hard at least since about 1970. Bird never won 2 in a row. Tim Duncan never 2 in a row. Kawhi Leonard never 2 in a row. Not Jokic (so far).
Some others who have 2 or more in a row further back, Jordan, Magic, Olajuwon, Isaiah Thomas.
I get the angst. They are underachieving. It seems like the title is theirs to lose. Just can't lose sight of how hard this is. Tatum and Brown in particular are going to have to raise to another level, the level of some of the greatest players of all time, if they want to go back to back.