I don't think a totally new approach is needed. We already have what we need to completely solve bufferbloat. What we're missing is universal deployment.
If we could get fq_codel on every router, modem and switch, then the problem would be gone and we wouldn't need any of the fancier TCP congestion control algorithms (but ECN-capable TCPs would still be nice to have).
If we could get BBR on every server and client device, then that would mostly solve bufferbloat (for TCP traffic), but probably wouldn't be as good as having fq_codel throughout the network.
Having partial deployments of both is sub-optimal, but even the potential negative interactions between delay-based TCP congestion control and delay-eliminating AQM should still be better than not having either and suffering the full effects of bufferbloat.
The ideal solution is to put CoDel in hardware where it can be cheap. FQ-CoDel would be better, but would require many times more silicon. It's probably worth it, but it's a harder proposition to sell to the ASIC designers.
Even on current hardware, anything that's currently handling packets with a CPU instead of fixed-function hardware should be able to add CoDel without sacrificing too much throughput. Home routers running SQM-style QoS run into performance problems not because of CoDel or fq_codel but because of the traffic shaping. When everything has AQM, you no longer need a traffic shaper on your home gateway router, just AQM, and the CPU requirements for that are vastly lower.
If we could get fq_codel on every router, modem and switch, then the problem would be gone and we wouldn't need any of the fancier TCP congestion control algorithms (but ECN-capable TCPs would still be nice to have).
If we could get BBR on every server and client device, then that would mostly solve bufferbloat (for TCP traffic), but probably wouldn't be as good as having fq_codel throughout the network.
Having partial deployments of both is sub-optimal, but even the potential negative interactions between delay-based TCP congestion control and delay-eliminating AQM should still be better than not having either and suffering the full effects of bufferbloat.