I have two separate change of boot stages. The trouble is, old boots are the comfortable old faithfuls, even if the grip and waterproofing isn't quite so good.
So I have the good pair (or if I am honest 2, one for hills and bogs, the other lighter weight for LDPs etc). Then there is the old pair, which gets used for local walks, the beach and so on, even if it does leak a bit and I wouldn't trust it on a slippy surface.
The good pair gets demoted when it starts to leak, grip goes etc.
The old pair gets flung in the bin when it falls apart or gets uncomfortable.
So it is sometimes more change of use than change of footwear.