I like the separation of responsibilities. But I see it in many teams where people take over additional responsibilities in order to help others. And do you know what is the end result of that?
Overstressed person, who has a hero complex. They think they help the company and the team, but in reality, they are doing a very poor job in all the responsibilities.
A better solution for this issue is to prioritize the work or find/hire additional people to help you.