You shouldn't really treat Warlocks as dedicated full spellcasters like Wizards, Sorcerers, and Clerics. They're much closer to martials in terms of playstyle. Think of them as magical archers who can occasionally cast spells.
The face of the party: that's why I used the sorcerer as a comparison.
The strength of the cantrip: a d10? Then you can elect to use an invocation slot to add in your attribute bonus. Now it's up to the power level of a heavy crossbow. Great, I guess. Shrug.
Your underselling eldritch blast a bit. It's worth mentioning that eldritch blast scales with character level to give you 4 attacks at lvl 17 (the same amount as 20th level fighter) which makes it far superior to every other cantrip when used with agonizing blast (4d10 + 20 vs 4d10 from firebolt). For 2 levels in warlock you essentially get a heavy crossbow that deals force damage, is treated as magical, ignores the loading property, and functions as well as if it was wielded by a 20th level fighter. Then you have other invocations such as repelling blast, eldritch spear, and grasp of hadar which make it an extremely versatile tool.
For comparison's sake, even paladins can't do as much single target damage as a warlock can without resources. They cap out at 2 attacks and get a feature to give an extra d8 to all their attacks for 4d8 + 10 (or 4d8 + 16 with a +3 longsword).
