This isn't meant to say that BBR changes are not worthwhile, but in reality if the size reduction is only 50% that is a small reduction.

Disk sizes are routinely measured in terabytes. Even SSDs are reaching the terabyte range now. Blockchain sizes for any of these coins are measured in the gigabytes or tens of gigabytes at most. On another thread someone estimated a CN blockchain with transaction volume comparable to bitcoin at around 60 GB in a few years. Obviously these estimates are highly innaccurate, but that isn't really the point. By the time this happens disk sizes will likely be measured in tens of terabytes. Whether the blockchain size turns out to be 30 GB (1/2) or 120 GB (2x) really makes very little difference.

I note in fairness that you did say at least 50%. If it turns out to be 90% or more, then perhaps you are on to something. But at 50% it is hard to see why anyone would care much.

Yes, I'm part of the XMR team so I have an an agenda here, as do you. However, others with no apparent agenda have made the same point, including I think dga who is now a visible BBR supporter.