Simply put, it depends. It's both perfectly fine to share an inventory, yet also fine to not share one. You shouldn't really be asking what people prefer, and instead ask yourself what will fit better for your game. Since you're doing an SRPG, let's look at two separate examples.
On one hand, we have Fire Emblem. Everyone can carry only up to five items in most of the games, meaning you need to keep track of inventory space. However, the Lord unit can access the convoy at all times, so you technically have access to all your items, but if you want another unit to have something, they need to stand next to the Lord, or you'll need to get the item to the other unit by way of trading (if you wanna be real fancy about it, setting up a trade chain is always neat).
On the other hand, take Final Fantasy Tactics. Your item list is shared amongst your characters, and with good reason. Chemists, for example, would be really poor if they only had a few individual potions to draw from for their extended range on potion use. Same for Ninjas and their Throw Weapon skill. Aside from that, it helps that everyone can pull from the full item list when a clutch Phoenix Down is needed, or just general healing if you don't have a Chemist or White Magic using character nearby. There's also the fact that even being able to use items is dependent on having an action ability equipped, so restricting the number of items one could use would be counterproductive.
Ultimately, you gotta consider what your game is going to play like, then decide from there.
I feel negatively about it. I've played games where it's a thing, and for as infrequently as I usually use items, it just adds a small layer of annoyance when I have to restock each individual character's inventory of items. Knowing it's in a game wouldn't deter me from playing it, but it would be a negative point in my review.
If you honestly docked a game points for this simply because you had to pay more attention to restocking, that would be kinda messed up. It shouldn't be that big a deal.