Depending on the campaign or DM the effects granted by a background could actually be "a lot" for the roleplay. For example an Entertainer being able to get free room and board for entertaining people can be a good way to save the party money and roleplay how the party is covered. And those backgrounds that grant a "contact" can create entire questlines or be an invaluable resource for learning things. It is all in how it is handled and what campaign they are in.
Sure. In a pen and paper campaign with a human DM.
But since every element of content put into BG 3 is going to be pre-generated by the developers, that would be a lot of work for a handful of options which couldn't come close to satisfying the possible range of players ideas for their character backstory.
What is the Hermit's "Discovery" feature in BG 3? That one literally is a big shrug and "work with your DM to figure out what it is". Some features might have possible uses, others few to none. So the better option is to just do what they did and leave the background as empty as possible.
