That has become clear, although -- as golfmad pointed out -- you did have a better understanding back in February. Take KARFA's advice and read up on BAEC when you have the time to do so. It's actually very good at the things it's good at.

Having a stash of miles can be extremely helpful if an emergency means you need to fly long haul at short notice and don't know when you will want (or be able) to return. This is less true of Avios redeemed for economy than of most other mileage currency and class of travel combinations, but it's still true.