Why no dueling?

[Ultimatecalibur]

Of course. That shouldn't be a reason against adding in the function though.

Duels can be a helpful tool for learning how to deal with situations with no pressure or penalty for "losing". If you keep getting yolo420swag rekt by ninjas in FL, duel one over and over until you're more comfortable against them.

FL and WD don't provide that opportunity since you're immediately under pressure to win, instead of learn.

Sorry, but your example is very poor. The main reason people get "rekt" by ninjas in Frontlines is their sneak attack/trick attack out of hide alpha strikes. That something a duel can't teach you to be prepared for.

All a 1v1 duel prepares you for are 1v1 duels. They don't prepare healers to be focused by more than one person. They don't teach Paladins how to properly cover and protect other characters.

So then let them?
I mean, christ
That's already happening with literally all the other content in the game, doesn't mean we should get rid of it.

This is a non factor to me, however. It's really no different than someone measuring "epeen" using ilvl and knowledge of raid or trial content.

Level of player toxicity would be on a very different scale. Taunting, harassment, duel invite spamming...