I'm more on team small tasks because of my love of unix piping, I keep telling folks, as a old Linux dude, seeing subagents work together for the first time felt like I was learning to pipe sed and awk for the first time. I realized how powerful these could be, and we still seem to be going that direction.
This isn't an argument you are making, it's just an assertion that you could make an argument if you are so inclined, but you won't be doing so at this time, but "science" is obviously on your side, but you can't be bothered to say how or even enough detail for someone to check what you are referring to. I can do that to, see my first sentence in this reply.
I don't know how LLM memory systems work. I do know that you don't have a lifetime of remembering everything with high precision. Not only do most people not remember the plot of most of the movies they have seen, they can't reliably list most of the movies they have seen. Not everyone has a good memory. My point is that it's not valid to reference a false model of how human memory works as a reason some specific LLM memory implementation isn't useful for solving some problems.
Surely with (much less than) 300K pages you could describe every meaningful detail of a video series' plot. You don't need to remember the exact pixel values.
You can also scale the numbers up. I specifically chose a relatively small model and short context length as a reference, so 100x bigger is not out of question. At that point, with a 10B token capacity, you are looking at all of English Wikipedia in a single state.