I've noticed this in the STO videoes I've seen on Youtube. Some players have full character slots. They have bought the maximum amount of space available for their characters and banks and it's all full of stuff. Window after window of stuff...
While I've bought some space for my characters I don't have a reason to carry several types of shields/weapons/consoles all at once so I sell off what I don't need. So my only guess is they carry equipment to deal with any kind of situation that they can swap out anytime.
So does anyone really need to carry/store so much stuff???
I'm a pack rat too, though I mostly collect novelties. Bought prototype Andorian weapons specifically because you can't get them anymore, and still holding on to some of those combadge item things that show up in your inventory when you buy a ship on the c-store from the website. Weird, I know. And I've got a rechargeable shield battery kicking about... ah, novelties.
I am a casual player, and I do it... I hate dying... If swapping gear helps minimize that, I am all for it..
Also, I've maxed all my DuOff levels, max reshearch skill, Got 95% of all the accolades, Done all the missions at least twice, been to every spot I can think of, have all the ships I want, and 3 years of skill-fine-tuning.
i only pack Zen and EC, i keep any Set items, XII purples of any type and cosoles blue XI or above go into the bank.
i got ALL Slots maxed, DOff, Bank, Accounbank, Inventory, on all my 10 Characters
i only do not care for BOff or Ship slots for some reason it has always been enough for me what i had already.... bought a few costume slots for easy swapping, those are the only account wide slots so i bought a few more.
i keep my inventory and banks clean, only things that are worth keeping stay in there, i have more room than i need and i like it!