I can understand your feelings. I admit it sucks when there are older generations comparing their times with today's, especially if the intention is for showing that they're better and tougher than the current generation. I think everyone in every generation has different struggles. I'm sure when they were young, whenever their parents said things like that, they didn't like it too.
But sometimes there are parents who tell stories about their hard past life without that kind intension. They're just want to share their memories. It's nothing wrong with that, and we'd like to hear it.
If the intention is to make their children more grateful with their life, I think parents should adjust the intonation of speech when they say it. So it more like motivational and educational stories than a judgment or invalidation of their kids' feeling.
Since the communication is the key, maybe you could talk to your parents about this? IDK it's gonna work or not, but I hope your relationship with your parents is getting better.