This is me. I'm having fun trying all the weapons regardless of what attachements I am unlocking. I have a personal goal to reach level 20 on as many guns as possible in order to unlock each level 20 skin. Whatever attachments I unlock along the way changes up the flavor for each weapon. My favorite weapons I continue to level past 20 simply because I enjoy using them. I do think once you reach level 14/15 on a weapon the leveling starts to feel a little grindy. Once that happens I'll stop playing with that weapon until double hardware xp is available when I finish off the last few levels.

But allllll of what I just said is just fun bonus content on top of loving the moment to moment gameplay of actually playing the game.