... which is great until a consumer or replica decides to replay a topic/partition from the beginning, and forces all the recently-written data to be evicted, adversely impacting performance for all the well-behaved consumers :(

> forces all the recently-written data to be evicted

That's unlikely unless 1) your hosts are seriously underpowered and 2) you have no per-consumer quotas set

Can you clarify what you mean by underpowered? Not every site wants to replace terabytes of disk with NVMe storage to make paging faster - especially sites that have a lot of throughput and long retention demands.

Second, even if quotas could be used - and there are plenty of sites where they cannot - there’s still a broker-replacement scenario that needs to be accounted for. Most folks don’t want to intentionally impede the recovery rate of a failed broker.