In 5e, Warlocks can also deliver Eldritch Blast (effects/damage) through Weapons like Glaives and such.
Eh? No they can't, that was in 3.5.
In 5e you can get a
Pact of the Blade pact gift, instead of the familiar, but that is completely independent (and mechanically inferior to using) Eldritch Blast.
Though Eldritch Blast, by level 5, will be doing 3d6 plus Cha to damage every hit so their damage does scale well IMO.
At level 5 Eldritch Blast (with agonising blast) should do 1d10+CHA bonus. But it should fire
twice.
The one blast for 3d6 at level 5 (actually 1/2 your level round up) was from the 3.5 version rules. You can find them in NWN2.