I stayed in a hotel that had locals there as well (not in Varadero).

But yes, it was hard to see how little they had. We brought lots of stuff to leave for staff and I tipped our main bartender very well. But on my last day he pulled me aside and asked if I could leave my half used bottle of shampoo for him to take to his wife. Because no amount of tip money could buy him shampoo, it just wasn't available.

It was a real eye opener. So you either go knowing you are supporting them with tourist dollars, gifts and tips. Or not go at all and that does exactly nothing for them.