It seems the Dev's want to lower the upper-level damage cap which may be getting out of hand while at the same time, keep low and mid-tier players relevant. If true, then a simple solution would be to incrementally lower the contribution your main resources have on your damage. These main resources ... Stamina and Magika ... are used in the calculations for most damage abilities.
As the player first starts out, the increase of their main resources are the drivers for their damage. They don't have the gear yet to boost other damaging stats. As the player starts getting gear which helps to boost their damage they still rely on those resources but they are not the only methods they can use to increase damage output. By progressively lowering the effect those resources have on damage output as the player levels, you would effectively cap those resources to a level which can be controlled.
This makes the end game player still able to maximize their damage within the scope of their resources while at the same time, keeping the low and mid-level player strong enough to eventually become a max-level player. Too simple?