ZFS remains an excellent filesystem for bulk storage on rust, but were I Apple at the time, I would probably want to focus on something built for the coming era of flash and NVMe storage. There are a number of axioms built into ZFS that come out of the spinning disk era that still hold it back for flash-only filesystems.
Certainly one would build something different starting in 2025 rather than 2001, but do you have specific examples of how ZFS’s design holds it back? I think it has been adapted extremely well for the changing ecosystem.
I didn't watch it in its entirety, but I'm familiar with Allan's work. There doesn't seem to be anything fundamental to the design of ZFS that his talk highlights as limiting, but there are many areas that have benefitted from optimization and tuning.
