Now that we can stack all the pet damage skill lines on one character, we need to have more options in our champion point perks to focus damage buffs for pet damage, and/or we need a new Mythic aimed at increasing pet damage at the cost of other sources of damage.
I've experimented with pet builds before and with all kinds of different armor sets and have had little success in making a pet build that is competitive in terms of damage output. It would be nice to have champion point perks (perhaps a new purple star) that offer perks geared towards buffing your pets damage and survivability. Combined with a new mythic, players could really lean into the pet build concept if they so choose to make the build more specialized and more effective.
We have champion points and sets designed for heavy attack builds, and this is another niche that I think needs to be more completely built out.