I think that spells have more metrics by which to measure usefulness than only comparing damage amount and type, and as a result it is not so easy to say that scorching ray completely outclasses chromatic orb.
Let's look at a few possible metrics to compare the two in detail (because I'm coming into this post without an opinion as to whether one spell outclasses the other or not).
Range: Both have enough range to cover the entire field of battle in typical encounter conditions, but scorching ray has the edge in some atypical encounter conditions.
Components: Scorching ray has the edge here too, since it doesn't require a material component of any kind.
Usability: Chromatic orb has a very slight edge here since it can be cast with any available spell slot. I say the edge is very slight because at a certain level, the damage of cantrips matches or beats the damage of a 1st-level casting of chromatic orb, and at that level other 1st-level spell options remain solidly useful (i.e. shield) so reserving 1st-level spell slots for those isn't unwise.
Versatility: Chromatic orb has the edge here, since scorching ray is only ever going to do fire damage (barring class features or feats that provide options not yet officially in the game), which might be resisted or ignored by a target, and chromatic orb has enough choices for damage type that it is unlikely to be resisted or ignored entirely by monsters that aren't resisting or ignoring all spells of level X or lower.
The Gamble: This one, I feel, is more subjective. Some people (me, for example) like the better odds of a big hit and don't mind better odds of a complete miss in trade to get it, and some people like the better odds of having some effect even if it means smaller chance at the big hits. It would take an in-depth look at the damage estimations of each spell given the actual details of enemies faced in the campaign to be sure which has an edge, so I'm comfortable calling this metric a draw.
Strategy: scorching ray has the edge again (in the general case at least), since it can be multi-target or single-target, while chromatic orb is stuck single-target only. A sorcerer with twin spell can change that a bit, especially given that a sorcerer might also add some bonus damage for choosing a particular damage type when casting chromatic orb.
So that's 3 for scorching ray, and 2 for chromatic orb with an extra nod to the spell if the character in question is a sorcerer with the right set of features. Which isn't, by my reckoning, a complete outclassing - even though it is clear that scorching ray is definitely generally more potent, which I think it should be, given that it's a higher level spell.