My question involves a marriage in the state of: new york (long Island)

My parents have been apart for over 20 years. Living in their own places, just seeing each other at holidays or family functions. They are both 76. Both receive their social security. Would it serve any purpose for them to get divorced via uncontested divorce? Dad has always said that if he dies first mom will get his social security because it's more. Aside from that is there any reason to? Dad has some money now so he can afford it. Thanks for any info. Ask any questions if needed.