The game is fun, yes, but for me I need to have some sort of sense of progression. I know I can still have fun after the goal is reached, but until then I find myself keep playing multiplayer games to achieve them.
For example, while I definitely enjoyed Halo Reach back on xbox 360, I played to grind those credits to unlock specific armor pieces. Once I unlocked them, I recall still having fun. Older COD games had gun unlocks, which some of them truly felt rewarding. BF games before V (or was it BF1?) had progressional weapon, weapon attachments, gadgets, and vehicle attachments without paying extra (not including dlc contents, which don't count).
With Halo Inf, while there is some sort of progression w/ f2p battle pass system there are only 25 cosmetic unlocks for the entirety of 100 levels, while the stuff you unlock with premium battle pass triple that amount. The rest of the free unlocks are challenge swap, which I find rather insulting. It doesn't incentivize me to keep on playing.
Halo MCC's free battle pass system, which let you put points into any seasonal pass of your choosing with no extra cost, had the right idea. Not sure why they moved away from that