When I played baldur's gate 1 I was really surprised to see how the same low level spell (magic missile) became stronger with level. I thought it was terrible design to have low level characters get it creating just 1 puny missile, while the assassin sent to kill me instantly generates 5 missiles, leaving Imoen on her own to somehow kill him and revive me.
I really liked the change in 5e where spells are only stronger when you upcast them, it makes the spells do what you can expect them to do, separating them from what your character level is.
Damage cantrips leveling up with you is also good imo, as cantrip damage is so incredibly low relative to enemies/other classes it's just a weak move designed not to leave casters completely helpless without spell-slots.
It's fine that low level slots are reserved for things that don't need scaling - fog clouds and greases and armor and shield spells scale with the effectiveness of the enemies power (if you make a stronger enemy miss, you saved yourself from more dmg). There is no need for all spell slots to directly translatable to damage.
