Most leveled spells that deal damage provide damage regardless, with only a few exceptions. Chromatic Orb is, unfortunately, one of those exceptions. Cantrips, on the other hand, are universally all-or-nothing; it's a hard and fast rule for them, regardless of their being attack roll or saving throw - and is part of the reason why so many people have been so vocally against guaranteed damage from cantrips via surface abuse.
Here's a little detail for you: The Sorcerer spell list, as of the recently released Tasha's Cauldron of Everything, contains 196 spells. Of those spells only eight (8!) leveled spells require or involve attack rolls, and that includes spells like storm sphere and wall of light, where the attack roll is secondary and optional. Add six to that number, for cantrips which require attack rolls.
The extreme vast majority of ofence spells offer saving throws instead, and the extreme vast majority of those are save for half damage - meaning you get something out of them regardless.
Remember also that there are fixed scaling rules for spells that are up-cast with higher level slots. buffing the lowest slot level would require further maths to filter through all of the up-casting as well, and it overall makes the magic system more mathematically complex than Wizards wanted for 5e. Older editions absolutely did have leveled spells growing by caster level independently of the base spell... it got to be a nightmare of processing though. Simpler is better, in this case, even if there are some edge cases which feel a little off (because you are right; in the case of an all-or-nothing leveled spell like Chromatic Orb, at higher levels, your cantrips will out do it at its base level, and that feels odd... the only consolation then is the elemental versatility).
