Eldritch Blast needs to becomboed with invocations to be effective.
Which ones? I don't see many invocations which have useful combat spells, so I guess you didn't mean combat invocations.
Agonizing blast, can give +5 to each eldritch blast, Chains of Carceri a hold monster like invocation, Eldritch Spear, Repelling Blast, Lance of Lethargy, etc.
In a game where verticality will matters a lot, repealling blast will be amazing. Think the possibilities. Rogues are approaching trying to sneak attack you and ... They got "repealed" to a canyon and take fall damage.
Or you cast black tentacles, the enemies are finally free and approaching and repealling blast then to the tentacles. Repaling blast can help a lot the party. Can save the life of a cleric, can put enemies back to a wizard AoE, can prevent the tank from taking attacks of opportunity, is one of my favorite invocations.
Patrons are one of the best features for RP in 5e, IMHO.
I agree BUT one big problem that i have is that many people seems to think that patrons are the source of the power and their relationship with warlocks is like cleric/deity and not master/apprentice. This is not the case on 2e(witch subkit), 3.5e nor 5e.