I have worked with a fair number of awesome developers. I was always stuck by how they had a deep understanding of not only what they did but the business area they worked in. They often saw things that others didn't due to that unique perspective - which you only get when you are 'in the weeds'.
With the tendency to strip things down, it would make sense that the ultimate outcome would be developers performing all the 'support' roles too - which would give them full autonomy on what they build and how.
And yet, this is not the norm. Or even fashionable.
This has been written about for decades and is a core part of Extreme Programming where the developers are customer facing and take on whatever role they need to create software be that as BA, QA, UX or UI developer or whatever acronym is currently popular.
When I think about each of those roles, I actually think of the bias they have. Each has a strong lean, which is core to that role - business analysts do lean more to business requirements and process, QA lean towards software that can be verified as working etc.
When I think about all those roles being covered by one person I realise that it's not fair.
It's not that a person can't do that but asking someone to balance all those areas and apply bias fairly or consistently is not something that we should ask from people. It can only lead to internal conflict, which we might not see or be aware of.
So yes, it's a pain to have those discussions with people. It's difficult and time consuming to find a compromise between the different members of your team, all of whom have excellent points and competing contexts.
But it's probably better that all that is out in the open. That we realise that our bias for our context is valuable in that discussion.
It might not feel like it but by having those roles, we are actually managing the biases that compete when we create software that people love to use. No right, no wrong just perspectives that need to be balanced.
Asking person to do that is unfair - only a team of people who respect each others perspective and value the context it brings to our own can figure that out. Somehow.