Are you sure you calculate that properly? You know that a Full Size Gem Pickaxe is worth 3 Material Units (which have to be high quality Gems) while the Gem tipped Pickaxe is 1 Material Unit (which is low quality Gems!)? You actually get MORE durability out of it if its just “half” as you say (It is actually quarter btw). And the Steel itself that is used is being fully ignored for this calculation too.
These Pickaxes HAVE a purpose, just not the narrow minded purpose that you think they have.
Not every Tool that exists needs to obsoletify other Tools. Every Tool is supposed to have a use, and you apparently chose the wrong Tool for the Job.