343 needs to completely overhaul the systems that incentivize players to get on and play matches. The current system of weekly chores to complete, and FOMO based events is turning players off.
Drop the Battle Pass and challenge system entirely. Create a long-term rank up system based on match XP. Individual matches reward some credits, rank ups reward more credits. Add a commendation library that rewards credits for commendation tier completions (as a means of boosting your credit income through targeted gameplay goals without any time limit).
Overhaul the shop so that you can view and buy Armor Kits (sets of matching armor, which will both appear in the kit section but will also unlock as individual items), or browse armor individually and buy it that way. The Shop should ALWAYS feature ALL armor, coatings, and other cosmetics that are in the game, and armor should never disappear when a season or event ends.
Then we can go back to implementing a form of limited time event to the game. But instead of being a FOMO based set of weekly challenges with a pass, it will be in the form of a temporary series of commendations that award event-based cosmetics instead of credits upon completing theirs. When an event ends, all the cosmetics from it get moved permanently to the shop, so players who missed fully completing the event can always just get what they don’t have afterwards for credits.
This will completely change the incentive for players to log in and play from “gotta do my chores for the week” to “I’m gonna play some Halo and save up credits for that helmet I’ve had my eye on.”
Credits will, of course, still be available as a paid microtransaction. And with the sheer number of cosmetics Infinite has, and will potentially have in the future player will no doubt still drop $ on the shop. But why players log in will be completely different, and it will give them a completely different, and healthier perspective of the game they are playing.