Oh no, memories and skills are terrible replacements for system prompts.
replyNot only they get "lost" and ignored as the context grows, but the baseline behaviour of system prompts is retained in the agent.
Memories are implemented differently agent to agent. They are usually implemented by yet-another-model-call, as a distillation of typed prompts (working memory). Conversational communication is messy with a lower signal to noise ratio than the distillation (semantic memory). Semantic memories are much better than appending raw historical prompts.
replySkills are prompts, albeit in a specific format. This is apparent in say, Codex where $MYSKILL is literally injecting the skill-prompt inline into a typed prompt. This all gets passed into the semantic memory system anyways, refining away cruft like redundancy, pleasantries, et al.
And none of this works properly. None.
replyYou have to remind it what's in it's own memory, or the subagent skill is influenced by the main system prompt.
It's sloppy vibe coders productivity porn.