Kaybee, your parents sound like a worse version of mine. Last year they had a financial crisis (Dad lost 60k due to risky investments, no job at the time), but still had a large enough nest egg that I would have been 100% fine for the rest of my life. They freaked out so bad that they were asking to move in with me and saying they were going to be eating cat food in 10 years blahblah. In reality Dad could have gotten a part time job at minimum wage until they could collect social security and they'd live in luxury til the end of time. Mom talked about how Dad's investing strategy was like a gambling problem (completely true). Then a few months later Dad was able to get a job that had a high enough status ranking for his ego, and everything snapped back to normal. They bought a new car (current 60k mile paid off vehicle was sure to need maintenance soon so getting a new car is totally worth it), new engagement rings, Dad starts up with his investing again and Mom turns a blissful blind eye.
Anyway your parents sound like mine, Dad makes bad decisions and freaks out, Mom turns a blind eye. Also every time I go there Mom is always showing me all the things she bought. "Look at these new shoes! this new bag! these new tops! I got them all on sale, what a great deal!" I swear every time I go there she has 2-10 new shirts and idk what she's doing with all of them.
Since I've already been through the "wait til they have a financial crisis and then try to step in and help" phase, I'm going to save you some time and tell you that you likely won't be able to help them. They won't listen, they won't be willing to change, and they'll moan "woe is me" the entire time. The only way would be to 100% control their finances. Soo yeah I have no good advice, but best wishes in dealing with that eventual situation.