This is a tough question to answer and you are going to get different replies/advice. Many of us have already left the game for the same reasons you have mentioned. The DZ hasn't really changed. If you didn't like it then, I don't think you will like it now. The game has also introduced Classified sets which are extremely powerful and without them you will be very underpowered in PvP although in PvE they are not strictly necessary.
If you enjoy PvE activities, of course the season pass and DLCs offer you plenty of new content but none of it really has any depth and for most of us it didn't retain our attention for very long.
Others will tell you the game is going strong. You would really need to try and join up with people like this and see if they are willing to help you gear up and carry you until you get your gear. Obviously only those content with the way the game is at present are those that are hanging around and continue to play. Many of us just find the game too unbalanced and the development team too unwilling to make changes for their to be any hope for improvement.
The Division is unique and trying to find something that has the same appeal is very hard. Unfortunately too much is wrong with it and not enough being fixed that coming back to it even after a break usually results in the same disappointment. Just like any sour relationship, you reach the point where you feel enough is enough and don't want to try anymore, especially when the other party shows no willingness to change.
You will have to make your own choice as to whether you feel it is worth giving it another shot.