At the most basic, if nothing else, gratitude makes you relax a bit, get your shoulders down, maybe even make reaching a flow state easier. And we humans are just experts at feeling ´´unlucky´´ about everything, so a bit of ´´oh, that was nice, well thankyou universe´´ is potent--and yes, I think the Feeling Unlucky is societal programming and something to escape, and yes magick is very much about escaping Control and feeling you have Luck, so...