It’s actually much deeper in meaning (psychologically) than most people might initially understand. Quite a bit of thought actually went into the current system we see as their ‘final product.’ I’m not advocating for or even defending ‘343’s’ monetization model, I’m just attempting to explain how it functions and works (or doesn’t work) from a business standpoint.
The act of ‘343’ selling several filler items players ‘wouldn’t otherwise bother using’ just to equip one item that they ‘would’ is quite genius, especially if the prices weren’t as outrageous as they currently are (this is ‘343’s’ and ‘Corporate’s’ biggest flub up). They should be raising the temperature in the pot ‘ever so slightly and slowly’ for us proverbial frogs (players who buy store items), but instead ‘343’ got ahead of themselves and cranked the heat all the way up to maximum temperature (’’’$$$’’’ profits, $8.00 for the color blue) at the start of their monetization program in regards to their flagship game, severely overestimating what ‘Halo’ fans would tolerate as acceptable prices and practices.
Remember, a lot of gaming companies in today’s modern world find it acceptable or even necessary to employ psychologists to maximize profit potential, especially when it comes to ‘games as a live service.’ Whales are mostly targeted in this respect to squeeze out as much profit as they can from a tiny subset of the overall playerbase who will ‘more often than not’ overspend on just about anything over both a short and long term period; they often have poor impulse control as well (which is a lucrative ‘added bonus’ from ‘Corporate’s’ perspective).
Let’s say you buy a store bundle for a simple charm or a weapon coating. Now let’s say you’ve acquired other ‘meh-ish’ filler items along with it ‘in the bundle’, no big deal, right? You might not even notice or look at those other filler items in the bundle you purchased for several days. Then you go back to customize something else on an armor core or weapon and notice that those other colors/charms, ect. you previously dismissed as ‘meh-ish’ filler items really pair up well with another item you own and recently equipped; so you decide at that point to equip those bundle filler items along with your other gear.
What this does is further highlight the ‘illusion’ of depth pertaining to character customization within the game itself. Other players will see lots and lots of combinations as more and more of these bundles are sold and mixed together.
The key here is that a player (we’ll call them ‘Player 1’) only needs to be interested in ‘one item’ in the bundle to potentially ‘buy it.’ When ‘Player 1’ finally does decide to buy the bundle for that ‘one item’, and then that bundle rotates out of the daily/weekly store, they could end up being a ‘walking advertisement’ for all of the other filler items in the bundle when they equip them. This leads other players (‘Players 2, and 3’) to ‘potentially be interested’ in several items in that bundle that they may not consider filler items themselves (maybe ‘Players 2 and 3’ consider ‘Player 1’s’ original item that ‘Player 1’ wanted in the bundle as a filler item), further perpetuating the advertising in regards to the bundle itself (all of the players essentially end up as free advertising for ‘343’ within the game itself when they buy and equip bundle items without even being consciously aware of their own participation in such a complexly designed system).
On top of that, ‘in-game’ you can go to any player’s profile and view or even ‘favorite’ items that they currently have equipped (yes, you really can do this). So if some guy goes ‘31-2’ on your team in ‘Team Slayer’ and has an amazing armor color scheme/store item combo on their gear, an impressionable individual might visit that ‘31-2’ player’s profile, favorite several of the items they have equipped, and wait until those items cycle back around into the store to buy them. Then they’ll look just like the guy who totally dominated in their game!
Tl;dr - By ‘343’ bundling items together, all of the players wearing store bought items become walking advertisements for those bundles. As players equip more varied items from different bundles, those items (along with filler items) get seen by other players in multiplayer, and those other players might potentially want those items for themselves. The advertising perpetuates itself through the players and their profiles, since ‘in-game’ you can go to any player’s profile and view or even ‘favorite’ items that they currently have equipped.