Imo it is more or less favorable for Artanis in those situations for a number of reasons.
Artanis selfsustain is significantly better over time where as Dehaka’s is a burst of sustain through farmable essence. When he’s burned this he’s not nearly as tanky anymore. Dehaka’s Drag is also the only relevant ability in his entire kit so if he misses this one you’ll basically never take damage.
Artanis is also one who can do exceptionally well without a healer because of this. You just need to practice how to maximize shield uptime and CDR windows.
D.va is also not better than anyone at anything. She’s more or less a waste of time since whenever her self destruct is on CD she just runs around trying to recharge it doing minimal damage and minimal disruption.
However I’m not trying to pick on you but I think this thread isn’t a hero problem but a player problem. Practice more with Artanis and you’ll see that these scenarios, especially in QM, won’t be much of a problem. The new matchmaking won’t help you because if you enter with this mindset you’ll find something else to blame it on.
Focus on yourself and your own improvement, don’t assume the worst in the game.
Also, if you’re trying to fulfill the tank role and only that in QM I’d suggest you go the following:
Reactive Parry>Shield Battery>Warp Sickness/Chrono Surge/Follow Through>Suppression Pulse>Phase Bulwark>Force of Will>Heroic Upgrade/Plasma Burn
This will improve your shield uptime assuming you’re not 100% comfortable with your shield resets. When you get more comfortable with watching your trait and have the CDR as muscle memory you can start using Shield Surge in burst scenarios. You won’t do as much damage as normal and it’s perfectly fine to tank with talents such as Templar’s Zeal or Amateur Opponent but this will give you every little tool that Artanis can stack on top of his defensives in his kit. However I’d recommend you do this build to practice him more and then try other talents.