Mending and pelt clothing

[Snowpecter]

Pelt clothing are so heavy and have less bolubility (reduse sprint)

I wish getting better in mending make these clothings lighter and and more mobile. 

[Lexilogo]

I very rarely have an issue with reduced mobility on gear.

The poor weight-warmth ratio is a more significant downside, however it's what better-balances these equipment items. Their upsides are that they are repairable with easily renewable materials, and very durable. Getting carry weight upgrades like the Tactical Backpack and Moose Hide Satchel will also assist greatly in dealing with the extra weight of hide clothing.

[UpUpAway95]

If you're playing on modes are baseline resources are not "Low," (Interloper) but are instead "Medium" (Stalker) or "High" (Pilgrim and Voyageur), you will find excellent clothing (like the expedition parka and snow pants) that is far lighter and almost as warm as anything you can make yourself... and you'll easily have ample cloth and leather to keep those items in perfect repair.  You may not be aware, but you can repair clothes also using fishing tackle (which can be crafted in almost infinite amounts) and you can repair your bedroll without any sewing kit or fishing tackle.

In interloper, it's an advantage that hides are used to repair most of these items since hides are essentially "infinitely" available; whereas, cloth can be in short supply in some zones even though there is still ample cloth available in the entire game world.  Also, since the player generally has fewer heavy items in their general inventory (e.g. no rifle, less food and "luxury" gizmos, the weight of the crafted clothing is less of a concern than one might think.  The mobility rating really only takes effect when sprinting, so it is also less of a concern than one might think.  You'll notice that when you start to climb, the sprint meter (which will have a read area blocked off at the top depending on your clothing mobiity) is replaced by a "hand" and that meter always starts out full regardless.

Personally, I'm happy with it the way it is.