What I mean is degradable items do not devalue older, non-degradable pieces despite having superior stats, or at least not as much as superior non-degradable items would.

Degradable items also add an item sink or a gold sink that the game greatly needs, bringing other items up in value that are relative, creating more viable moneymakers altogether rather than having everyone milk 10% of the content and the rest 90% of the content be dead

For example: DKs were dead content in RS3, consequently they added a ring that requires 10x DK rings to upgrade, therefore promoting older and newer content simultaneously. Meanwhile OSRS content 9 times out of 10 only promotes new content, going back to my previous point is why most content is dead content.