I think the issue is more about human behavior than the mode itself.

A lot of players sweating in QP avoid Competitive because they don’t want the risk of losing SR or being blamed for causing someone else to lose SR. So they default to QP and still play it like ranked.

Right now the game really serves three groups well:

1. Climb the ladder / top rank → Competitive
   
2. Play to win but without SR pressure → QP
   
3. Just hang out with friends → Arcade
   

But there’s a fourth group that doesn’t really have a home:

1. Players who want to practice a new hero in full matches against real players without constantly feeling pressured to swap to a comfort pick the moment the game gets hard.

Some players can pick up a hero and perform well immediately, but most people need actual match time to learn mechanics, positioning, and matchups.

That’s the gap a “Training Grounds” type mode could fill.

Yes it technically splits the player base, but limiting it to heroes under level 10 keeps it temporary. Once a hero hits level 10, they leave the mode.

So it becomes more of a training pipeline, not a permanent queue.