Its the little stuff I took for granted.
Like the Token system for example. Every game now is all about bounties/achievements/etc. From headshots, to finding locations, to opening boxes - you get to choose from random passives that stick to your account and apply to all characters. shyt is lovely how they just constantly throw rewards at you. Skill system allows all kinds of flexibility between playstyle and gear. Unlike a lot of games in the genre they understood how to make a build around passives too. You get DRASTIC changes in playstyle just making minor tweaks and its all because the foundation is on point