As someone who has been playing a Sorcerer for 7 levels, yes, it's definitely a major addition. You have double the spells known at 1, 3, 5, 7, 9. 4 instead of 2 at 1st, then 8 instead of 4 at 3rd, etc. I'm not seeing the redundancy. Look at Life Domain. Bless? Not redundant -- sorcerer can't do anything like this. Cure wounds? Again, nope. Lesser Restoration? Still no redundancy. Spiritual Weapon? Big damage as a bonus action, no Concentration, nope, nothing that regular sorcerer can do, not redundant. Beacon of Hope? Revivify? Raise Dead? Shall I go on?
It's double the spells known from 1-9 and drops down to "only" +66% at level 20. Not just dragon sorcerer, also wild sorcerer, aka any other origin.
I agree, I'd prefer +CHA to fire damage too, since it's stronger when you do AOE attacks that hit multiple enemies. Extra Attack isn't too bad though, it's basically an 1d6+stat (shortbow for example) and combines well with things like divine favor, quickened hold person, haste, etc.
I'm clearly saying that it's overpowered compared to the other two origins. I brought up the other origins, and nowhere did I bring up other classes. If you want to complain about sorcerers being weaker than other classes then this isn't the thread for it.