Allocation =/= usage. DCS is designed to allocate as much memory as it can to itself, which can appear as usage in Task Manager. It doesn't necessarily mean it's using all of it, just that it's holding it reserved - this is why lots of people can have good performance with <64GB, and still see enormous memory usage the moment they upgrade.
Even when you do have usage higher than 32 gigs (possible in the case of users like yourself), a lot of the data DCS stores is not high priority, like unloaded terrain, and you won't see performance suffer even if it's streamed occasionally from an SSD pagefile. With that and the price of DDR5 in mind, 64 gigs just doesn't make much sense in my opinion.