Zardnaar
Legend
At 5th this build is still behind the archer. The archer has a better stat and style for 15% increased hit chances and good base damage. The archer is doing 16.1 damage a round against AC 15, you build is alternating 10.75 and 21.5 every other round (you quicken EB, next round you burn a spell to get the points back so you can quicken again -- you only have 3 sorcery points). Your 2 round average is 15.425.
And, again, this is ignoring fighter subclass, which can make a significant difference in fighter output. Or a ranger, who, depending on subclass, will get nice damage bonuses and can tie anything you do with Hex with Mark.
This combo only really gets rolling after it can spam quickened EB 3 times in a row, so sorcerer level 6+ or character level 8+. Even then, stat is +4, fighter is sitting at +5 with an extra ASI for goodness and you're still trashing your slots to power the combo.
As an aside, I've long ruled that Warlock spells don't mix with other class spells, so no burning Warlock slots for sorcery points or adding metamagic to warlock slots. I may rule that your can only use Metamagic on Sorcerer list spells, as that seems like it would reduce the cheese of dipping Warlock for EB and Agonizing blast to a dumb move.
Honestly, the problem here is the poorly done wording of Agonizing Blast and Sage Advice choosing to rule each beam as a separate instance of EB.
Brainfart on the sorcerer HD thing.
I'm saying the Sorlock though at higher levels is very competitive in terms of damge at higher levels it wins and you still have the option of doing other stuff, in practice you are not quickening beams all of the time.
Even at lower levels though with hex 1d10+charisma+ 1d6 is not bad damage and you get an extra beam at 5th level.
Boring? perhaps but you have options and it helps to think of your character as an archer and not as a spellcaster. Eldritch blast spam doesn't seem that much more boring than say being an archer.
The Sorlock is decent from level 3 on and becomes very good at higher levels. You can still drop a fireball if needed or a hypnotic pattern. 1d10+4+1d6 twice a round is competitive with a fighters 1d8+4 twice a round with +2 to hit level 5. Its also force and magic damage as well. The fighter can action surge say 3 times a day, the sorcerer can sacrifice a level 1 and 2 slot and quicken 3/day with the option to nova and sometimes you don't get 2 short rests.
The Sorlock (3 Sorc/2warlock) is dealing more damage than the fighter and still has 3 1st level spells, a 2nd level spell and 6 1st level warlock spells to use (assuming 2/short rests) and has 5 more cantrips as well. Its another 11 sorcerer points available (lets call it 8 you probably want 3 hexes) so you can quicken EB an extra 4 times.
The Sorlock is dealing more damage, has more options. This changes with the sharpshooter feat true but base damage is in the Sorlocks favor . At level 5. And it keeps getting better, your higher level Sorlock can quicken way more than the fighter can action surge, even at level 5 you can easily do it 7 times per day the fighter needs 6 short rests to do that.
The main point is we heave a spellcaster who is dealing more damage than the fighter at will and has other options and feats are also optional, sharpshooter is required.