Spend any length of time on these forums and you'll find a thread about someone questioning how any player can perform such low dps in any breadth of content. While suggestions for fixing this range from the feasible to the downright impossible, my brief research didn't find companions as the answer. (Do let me know if this has already been suggested to better results.)
Right now, companions only appear in group content when there's not enough real players to fill the slots--a fairly niche use for their potential. But what if companions were dynamic? Popping in and out of combat with you when your personal dps was below a certain threshold for certain content--obviously nothing competitive; just dungeons and vet dungeons.
Imagine a player, uh, doing whatever they think is amounting to sufficient dps (when it isn't), when suddenly Mirri jumps out of the shadows and says, "Looks like you could use a hand!" and begins attacking enemies appropriately until your dps reaches a fair threshold. By this, she is simply doing the most damage as per your build of her without stepping into tank or healing roles. Or maybe in these moments, companions add a flat range of dps, say up to 10k.
We have to realize that this brings up talks of pay-to-win because, until ESO is bundled with the Blackwood chapter, someone would need to purchase Blackwood in order to access this dps supplement. But I'd argue that a Venn Diagram of people that don't already own Blackwood and that still produce poor dps would reveal a small amount of players affected by this.
I want a solution to unfortunately queuing with low dps output players as much as anyone. I think companions need to be looked at as a solution now that they're been out for awhie. Not only does it allow these players not to get kicked for poor performance, it gives them a clear visual cue that they are underperforming. Could they simply not care? Of course. That's always a possibility. But an objective mechanic can be more persuasive than an abrupt kick or lots of shouting from team members to "get gewd". Heck, the companion could even stick around after combat for a minute and call out, "Come talk to me if you'd like some pointers for next time". When you talk to them you can have an option that says, "How did I do?" and they tell you your damage and how it can be improved--no different than when you die and the death recap gives you tips on how to survive.
Thoughts?
EDIT: Perhaps anyone's companion (or the most dps-built) could step forward and help a player (with all the same functionality), phasing to only be seen by the player lacking in damage? That way it isn't up to every individual to train their companions.