Size and Weight

I think the terms are confusing. Especially how weight is used.

Shouldn't weight be called volume and size be called weight?

In other words:

A block is like a backpack. It has a limited volume (4MWU, currently we call that weight). Fees are based on how heavy it is, aka weight (currently called size).

You want to pack as many valuable transactions in there until no more fit in (Knapsack problem). Valuable meaning sats per vb (or sats per weight, which we currently call size).

Am I missing something? I believe the terms are effectively swapped for what they mean.