> Compounding this is memory. It is extremely primitive. ... Now consider what happens over time as the agent learns more and more about you. Does that all get included in every single query? It eventually fails under its own weight.

Agentic coding has all of the same issues and it gets solved much the same way: give LLMs tool calls to file persistent memories by topic, list what topics are available (possibly with multiple levels of subtopics in turn) and retrieve them into the context when relevant. Not too different from what humans do with zettelkasten and the like.