I can see some people finding the gameplay too repetitive but I never got tired of it during the almost 50 hours it took me to finish the campaign in single-player mode. It takes some of my favorite things about the previous Ghost Recon, a linear tactical shooter, to an open world, mixing two types of games I really enjoy in a very satisfying way.
The gunplay is very solid and the story is nothing surprising but enough to add a purpose to the missions which, while not too diverse or intricate, I quite liked, thanks in great part to the freedom being in an open world adds to the way you can approach many of them. There are a ton of missions to do and collectibles to find, but it's the open world itself what really impressed me, the map is huge and varied, probably my favorite from all the similar games I've played, with a good number of different looking areas full of beautiful and interesting spots. Its vastness and realism made driving or flying from mission to mission, looking at the scenery, a wonderful experience in its own right but also made me more immersed in the game's story.
More info: https://en.wikipedia.org/wiki/Tom_Clancy%27s_Ghost_Recon_Wildlands