If you're still clinging to old pieces of Destiny 2 armor after the release of Shadowkeep, the new changes Bungie's promising for the "Armor 2.0" system might be enough to get you to ditch your Guardian's outdated duds now. By the end of October, armor mods will be added to Destiny 2's Collections tab, and at the start of Destiny 2's next season of content, "Armor 2.0" will be revised to introduce more broad-category mods and will allow players to stack mods of the same type on a single armor piece.
Outlined in the latest weekly update from Bungie, the first armor change coming to Destiny 2 after the big Shadowkeep revamp will make mods easier to manage. Since the new armor mods aren't currently part of the Collections tab, it's difficult to see which ones you have and which ones you've yet to find. For a system that's all about streamlining your Guardian's build, having to check a certain armor piece of a specific elemental type to see if you even have a mod is, well, inefficient. Being able to see all the mods, including which ones you're missing, in the Collections tab should make build-crafting a bit easier.
The 2.6.1 patch coming to Destiny 2 later in October will add armor mods to Collections tab. Another update at the start of Destiny 2's next season of content will add mods' energy cost and type to the Collections UI.
Additionally, Destiny 2's next season will make "Armor 2.0" customization a bit more flexible. As it stands, most mods have elemental affinities that mean they can only be applied to pieces of armor with the same affinity, and players can't stack two of the same mod on a single piece of armor. Next season, Bungie's granting two free broad-category (no elemental affinity) mods for the ammo finder and ammo scavenger categories to all players, and will let players stack multiples of most mods. With these changes, Bungie isn't moving away from elemental restrictions on armor, and stacking identical mods will apparently provide diminishing returns in the boost they grant, but both tweaks should allow for more variations in builds even if your mod collection is a little scant.
If thinking about armor customization and builds is still above your fledgling Guardian's pay grade, USG's guide section has everything else you need to know about Destiny 2: Shadowkeep and Bungie's new free-to-play offering, Destiny 2: New Light.