The problem is not that there is no one person it's that the team that knows the details are insulated from end users by layers of layers of bureaucracy needed to keep them from being flooded in identical/trivial tickets to the point where they never get to look at the actual product they are developing.

With smaller outfit's the L2 tech support might actually be having a line of communication directly to engineering, where in large companies there might be an L3-6 plus different product owners and escalation managers involved before a case gets in front of the engineering team.