[wtallis]

You're right: CoDel and derivatives like fq_codel and cake don't auto-tune anything on timescales much longer than the interval parameter which defaults to 100ms. And fq_codel doesn't even do traffic shaping.

But I think davecb may have been confusing traffic shaper limits with TCP congestion control behaviors, and maybe the impact of a large TCP initial window releasing a sudden burst of packets that may be large enough to build up a bit of a queue on particularly slow links. (It was a serious problem in the ADSL era; now, only wireless gets that slow, and large bursts of packets are as likely to help as not when frame aggregation enters the picture.)