Have you played a warlock multiclass?
Also, sell me on being a single class warlock! After you've dropped your 2 spells, what do you do to contribute?
Deflection and avoidance of the question by forcing another question on me? I think that answers my question. And, yes, I've not only played a multi-classed warlock, I've played a pure warlock and a pure bard. In fact, my last warlock made it to level 12 before dying.
What do I contribute? Plenty. I focused on a highly social tiefling-fiend warlock, using a combination of my Thaumaturgy and Hex, plus a few other spells to be highly adaptive. I was free with spells during social pillars, because high chance would yield a short rest before we got into a combat situation. Short rests may be rare during a dungeon crawl, but towns generally are friendly enough where I could rest before worrying about engaging an enemy. Combat wise, I didn't bother maximizing my damage with Hex usually, and instead went with things like Command or Darkness, or just Levitated out of reach once the ranged opponents were dealt with. Setting up the field round 1, then eldritch blasting on par with an archer, was good. I wasn't min-maxed for damage, but I didn't feel the need to be - I had the areas I shined in, and let others shine in their areas.
Exploration wise, I had Levitate and Detect Magic at will, with a side of Investigation and Arcana with a decent sized INT score to help me out. You'd be honestly amazed at how much at will abilities like that work awesomely in tandem; a wizard would have to drop his Concentration spell, while I just didn't care with how often I could cast. Pits? Laughable. Traps? Found them with as much frequency as a rogue, maybe a bit more with Mage Sight up. And that's before we start talking about having a good chunk of my ritual spells aimed at divinations. Yes, a wizard or cleric could gain a feat to match my warlock's, but a sorcerer, bard, or druid? Not a chance. We had an issue with a decision, I could make contact and get answers.
I also had a ring of spell storing, giving me more spells a rest, and a Rod of the Pact Bearer. While still a concern, spell slots were far less a worry for me. Its amazing what the right accessories will do for a gal.