The key thing to remember:
Tradeable does not necessarily equal easier to obtain.
Tradeable allows you (Deca) to have a lever to control the availability. If you judge an item too easy to obtain and is spoiling the game, you would reduce its drop rate so pushing up its value and lengthening the path to get it.
And you can set drop rates that would be brutal for players farming their own things (1/10000) but across the game population still means 1 or 2 a day get farmed.
Obviously every player sets their own goals, but speaking personally, knowing that an item costs x life gives a very clear short term goal: farm x life, to go and trade for the item. Or I can choose to “PPE” and go farm my own item. Under soulbound I have no choice, it’s farm my own or do without.
In general, it’s a sense of freedom to do what you wish with the loot you get. The UT Exchange sounds like it will help address individual farming frustration though it won’t fix where a friend desires an item and you loot a needless extra one that you can’t share with them.
The best thing about unsb is it lets players get ahold of any item on a whim. Lets say I just died with a ST set that I loved playing on. I have 3x spare items but not the ring. Unsb would let me get the ring through trading and then jump straight back into playing. This makes for a good combination with permadeath.
It brings every part of the game into play. If you love Sprite Worlds you can farm 2000 of them and honestly if you have that dedication to the game I won’t begrudge you trading your loot for a Crown.
(It’s true that a bad thing about unsb is it promotes RWT of items although please bear in mind that there currently already is RWT of whole accounts due to sb, so it’s not like soulbinding solves that. And Ring of Decades arguably one of the best items remains unsb and we get along fine with that.)