Personally, I've learnt not to expect anything from anyone like a "thank you" when doing something nice for them. But it doesn't matter to me because I don't think people are required to do anything in return for acts of generosity, although I try to my hardest to return the favour and be thankful when someone does something nice to me.

I distrust complements for all those reasons you listed, but also because growing up compliments were always given in a snide, backhanded way. And often just used as sarcasm to express discontent, so every compliment would mean the opposite. So, like the example you gave of coworker saying you work hard, I would take that as the opposite and them expressing discontent.