Do you think there are any "dead levels" in 5E?

[Nagog]

I'm really surprised at the lack of love for 1st and 2nd level spells here. My Sorcerer has been killing it in CoS; webbed some skeletons on skeleton warhorses last session and burning hands (empowered) a handful of shadows in an earlier session. In both cases we just had to mop up the remnants after that.

To be sure there are some good 1st level spells for those levels; I have used Sleep to great effect on more than one occasion. The issue comes down to reliability. If I only have 2 or 3 spell slots, to cover all of the pillars of play (for sorc/wiz it's typically combat and utility) it means you'll be Nova-ing your spells until you are a high enough level that you can lose a few slots without it making an impact on your resources.