If you just care about maximum damage, then EB is certainly the easy way to do it. Whether or not you can beat it with bladepact with the right build is a question for people who are not me.
However, you can still be effective with weapons and the supporting invocations. Your spell choices would change, in all likelihood -- much more using spells to support your melee than to dish out maximum initial damage.
Eldritch Blast, particularly if you take Agonizing Blast is going to be the bread and butter of most any Warlock. Great range, great damage, great versatility in target selection, great damage types, great utility with things like Repelling Blast - truly one of the best damage cantrips in the game. The only real exception is going to be the Hexblade subclass, which is designed around weapon use.
I will note, Fireball and Burning hands are really not your best use of your very limited spell slots. When you have limited access to a resource, you want to use it in the most effective way possible. Pure damage is usually not as effective as something that changes the flow of the battle itself - Hunger of Hadar, for example, deals repeated damage over time, controls the flow of movement of enemies by creating an area of denial, and could even sequester an enemy if they cannot escape the difficult terrain. Unless you are in a situation where a lot of enemies are grouped together begging to be hit with Fireball, something like HoH is a more efficient use of your spell slots.
6th level warlock (2024 rules)
So it seems to me I might use a couple of spells, fireball, burning hands to dish out initial damage.
After that, using a vanilla warlock you have two eldrith blasts doing decent damage.
Its just not worth going for any weapons right? You are going to do more damage with eldritch blast?
If you just care about maximum damage, then EB is certainly the easy way to do it. Whether or not you can beat it with bladepact with the right build is a question for people who are not me.
However, you can still be effective with weapons and the supporting invocations. Your spell choices would change, in all likelihood -- much more using spells to support your melee than to dish out maximum initial damage.
Eldritch Blast, particularly if you take Agonizing Blast is going to be the bread and butter of most any Warlock. Great range, great damage, great versatility in target selection, great damage types, great utility with things like Repelling Blast - truly one of the best damage cantrips in the game. The only real exception is going to be the Hexblade subclass, which is designed around weapon use.
I will note, Fireball and Burning hands are really not your best use of your very limited spell slots. When you have limited access to a resource, you want to use it in the most effective way possible. Pure damage is usually not as effective as something that changes the flow of the battle itself - Hunger of Hadar, for example, deals repeated damage over time, controls the flow of movement of enemies by creating an area of denial, and could even sequester an enemy if they cannot escape the difficult terrain. Unless you are in a situation where a lot of enemies are grouped together begging to be hit with Fireball, something like HoH is a more efficient use of your spell slots.
If you are asking if it is okay to be OP? Yes.
Or, you could do Hypnotic Pattern to immobilize enough of the opponents so that the rest of your party can chop them down, one at a time