I think they are exactly what you called them: a gamified player convenience.
I don't mind them when it's for the sake of saving travel time, such as when you just need to return to a merchant or a location you've previously visited.
However I do think there should be some sort of restrictions to where you can use them, somewhat similar to how there are some soft restrictions on where you can rest.
To use an example from my playthrough:
After I had reached the goblin hideout I ended up sneaking in by smashing a wall on the upper floor outside of the temple. This allowed me to move around inside the temple by sneaking around on the rafters far above the ground where none of the guards would see me. To my surprise there seemed to be a couple of tiny treasure chests stowed away up here, so this is definitely one of the intended ways for you to be able to enter the temple. I used one character to jump around on all the different paths. By following one of them I eventually made it inside one of the treasure rooms where I could plunder some crates full of coins and weapons.
However, there was one problem: I couldn't find a way to jump back out. My character could jump down into the treasure room, but the wall was too tall for him to jump back up. The only way I could leave the room would be through the guarded door, an act that surely would alert the guards standing right outside it.
...or I could just teleport to the waypoint in the Goblin Camp and run back as if nothing had ever happened.
This creates an interesting situation where the player (in this case that'd be me) can choose what to do and how far they're willing to roleplay.
I could have my remaining party members follow the same path I took so all of them would end up in the treasure room and then try to fight my way back out.
Alternatively I could send the three party members on a Saving Private Ryan style rescue mission deep into the enemy territory where they could free the one character trapped inside the room.
Both options would be small self-contained adventures, but when you also have the option of just teleporting the handful of steps outside the dungeon the intense feeling of pulling off this rescue mission gets kind of... diminished. I know I'd feel like I intentionally went out of my way to avoid using resources available to me solely for the sake of not living with the consequences of my actions.
I know it's always up to the player to choose what they want to do during their playthrough and that it most certainly isn't any of my business to dictate how others should play the game. But I still can't help but feel that if the option of teleporting out was unavailable the rescue mission would feel much more real. I'm sure there are plenty of other people who ended up in the exact same situation as me and I think it'd be a shame if they 'wasted' the opportunity for an impromptu quest like this just because they chose to teleport outside.
I think it's a good example of emergent gameplay, but giving the players a way to escape without consequence ends up diminishing the gravity of the moment.
