Anyone who has played games will understand that inventory constraints are a huge issue in many games. One developer has made an effort to clear up any misunderstandings when it comes to that issue. Brenon Holmes is the Technical Design Director on the upcoming BioWare game Anthem. He took to Reddit to respond to a Destiny 2 fan's question regarding that exact issue. The answers he gave might surprise some.
According to Holmes, the inventory constraints rely on a few different factors: UX, storage, bandwidth, and architecture. He explained that while a thing seemingly as simple as, “Why can't I have 100 items rather than 40?” can be quite complicated for developers. The UX reasoning for smaller inventories is fairly easy to understand. If you have 400 items, it'll take longer to load the game. Smaller inventories work better. Storage is another relatively easy thing to understand. If you have a ton of items, the game save data will take up more space on your system. Smaller inventories mean the game takes up less storage.
Bandwidth is another factor, according to Holmes. If you have smaller inventories, it will take up less bandwidth to send to the player. For larger amounts of inventory slots, it would cost more in bandwidth. Then there is also the company's technology. Some simply do not have the architecture and ability to support larger inventories in-game.
Holmes responded to this question using his experience as a game developer, and especially now for his work on Anthem. He stated very clearly that these might not necessarily be the reasons why Destiny 2 specifically has smaller inventories, but he imagines they might have something to do with it. Hopefully this helps clear up a question that has probably been plaguing gamers for quite some time.
Source: Reddit  &  via Game Rant