Original Destiny started out with abysmally piss-poor storage in terms of amount. They increased it, but the increase was still way too small. They may have increased it even more later, but by that point I'd already punched out and will never give a single shit about the franchise again.
Sharing it between characters actually makes it worse, not better. Sure, it facilitates trading between characters, but if I'm playing three different classes I'm going to have three times as much shit I want to store. So my shared storage basically winds up being 1/3rd as useful to me as it would be if it was fully separate (though shared storage is fine if you can have massive inventory).
It also didn't help how they handled shaders/colors, where you'd have to keep a shit-ton of shaders taking up inventory spaces if you ever wanted to change your colors around, or you'd basically just have to pick one or two color schemes and stick with them (at which point the entire concept of shaders as rewards - or worse, microtransactions - becomes frustratingly pointless). Though Destiny 2 decided to handle those waaaay worse (at least in the beginning - again, I've kind of stopped paying attention to how they handle stuff because I no longer care about the franchise at all).
I'm not even sure I'd accept "server space" or "bandwidth" as acceptable excuses for why you need draconian limits on storage size, because it would only become an issue for a minority of players, and because it doesn't take up that much data to store non-unique item IDs in what is essentially a text document list.
It wasn't the only problem I had with Destiny, but it was definitely a factor in why I quit.
lmao
boot up destiny 2 and see if you can even understand what anything is now
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that's one body that'll never be found you see, little sister don't miss when she aims her gun