To me Far Cry 4 was a huge step down from Far Cry 3.

Far Cry 3s gameplay loop worked for that game and that game only, since it worked by looping in the gameplay with the narrative, With every upgrade you got both you and Jason Brody were getting better and more intuned with the jungle, both making Jason a more blood trusty killer and making the gameplay loop more fulfilling.
You don't get that in Far Cry 4, you get a protagonist who's pretty much just a blank slate, a cast of characters that are unmemorable, and a gameplay loop that feels more like a checklist of things to do rather than feeling like you should do it.