Elsa’s reason explained better.

https://meltthefrozenheart.tumblr.com/post/714588474126319616/mattias-are-you-really-queen-of-arendelle

Elsa's ending in frozen 2 is so much more than just some freedom and acceptance or something.

Plus jen lee and Chris buck said clearly that they really wanted to show just how happy Elsa was in arendelle with her family.