Although Warlock is pretty much the fighter amongst casting classes, it has one very important perk;
Free knockback on EB. This is not to be deminished or taken lightly in the slightest.

I believe I ran Misty Step, Scorching Ray/Shatter and Invisiblity on mine next to the mandatory EB+Hex,

Warlocks are simple builds, often described as one of the dip classes, But repelling blast is so freaking good in this game. I do not care how hard a ranger or a fighter hits when I can throw everything off of anything.
The mage tower robot in the underdark? Yeeet
The Green Hag? Yeeet
Queen Phase Spider? Yeeet
And there is more yeeting to be done.

I don't entirely agree with the criticism that they're that bad raw damagewise and I find the 'your just a heavy crossbow with a few spellslots more' argument grossly thick.
With the right evocations and hex etc a warlock hits for 1d10+CHA+1d6 damage. This is pretty solid but not shocking.
It hits better than the cleric and better than an average wizard. the only class hitting higher would most likely be a ranger, or a fighter, which in turn can be argued; what exactly makes a ranger or a fighter more interesting than a Warlock both are vanilla combat classes? I've played all of them and they were allright,
Although I did like the Warlock best because of the better Charisma stat which helps with NPC Dialogue/trading etc.

All in all, Warlock always has been kinda meh, but from a 5e perspective, it;s a charisma character with some combat prowess. Kinda linear, not very complex. But can be made lots and lots of fun in the right hands.
As with any character or class really.