With the new Ultracode modes in Claude Code and Codex it's been taken to the next level. I mean, multi agent systems have been available for a long time, but the newest models seem to be much more RL'd for them.

Both GPT-5.6 and Fable will happily run 3+ hours straight off a relatively simple goal in that mode, burn through millions of tokens in the process.

Not saying it's great bang for your buck, but just that those modes are there and being pushed by the companies.