If they coded it where at certain intervals the companion's gear would update, that would be amazing.
Also Temple Trekking update when?
I have a WIP design that took the structure of temple trekking but with character companion customization (and level up). However, instead of the player doing all the fighting and the NPC's being useless... The player could only play as a healer who had to support their group of adventurers and use skilling to clear the path and make food/potions. The idea was to be a Farming/Herblore/Cooking activity.
I stopped work on it though as I'm not convinced we can actually do that level of NPC customization without some heavy engine support (I think). Also, if we are to do anything - as you said - we should probably update Temple Trekking to not be so bad/inconsistent.