You should be pulling a minimum of 2 packs per pull after level 50 and wall to walling in most instances after 60. Your healer is probably wanting you to go faster because we have literally nothing to do if you're not taking enough damage to actually heal you. We have a million healing abilities and 3 damage spells. Spamming holy and gravity is only so engaging compared to...actually needing to use my healing abilities. As long as you use cooldowns you will be able to survive most double and wall to wall pulls in game.

Even Thancred can do wall to wall in Shadowbringers dungeons, so I have to disagree with the notion of single pulls being the intended way to play through dungeons.