Sometimes in life we make sacrifices - a Golden Wedding is a HUGE milestone, not commonly reached these days - by the sounds of it - my parents were as different from yours as can be; but at their Golden Wedding dinner we had all the grand-children / step grand-children there my dad said it would probably be the last time we will be together as a family - he was right

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The Christmas before we lost him - it's complicated - but we didn't spent it together - 5 years on I still can't reconcile with that.
Last year, the rest of the family came together for my mum's 80th - I should have been in hospital for major surgery cancelled at the last minute - so my partner arranged to take me away - I'm still struggling to reconcile with that and my mum is still with us and I hope for many more birthdays to come.
People can and do die at all stages of life - many things over which we have no control (try never to part on an argument)
But there comes a certain point in everyone's life where the risks of something happening increase - your parents may make it to their 60th and beyond - or they may not, they may be physically incapable of their holidays - they might not even know who you are.
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You might hate the idea - I'm not a socialite these days - but sometimes in life there are things that it is vital to do
For memories for an unknown future - for peace of mind in an interim window id god forbid something happens before their Golden Wedding.
Their lives will be richer for knowing you were willing to make that sacrifice - if you don't - unless you are completely able to sweep things under the carpet and not give them a second thought (the very fact you are asking the question suggests you aren't) - then I promise you it will play on your mind for a lot longer than the week or two of the holiday. If your OH doesn't go is that a major problem? (I ask because being disabled, for me, it would be a problem)
I should add I have the whackiest extended family you can ever imagine (ex-wifes, half siblings / step siblings / step grandparents - the net is HUGE) - none of us were socialites - but those rare events where we did get together like key nirthdays were good events and I'm glad I didn't miss them.
It's just my opinion - I'm sure others will disagree. We don't always approve of the way our family behave, and some are quite happy to absolve themselves of all connections.
When we love people - sometimes we make sacrifices as a way of demonstrating that - or live with the conscience and your own unanswered questions if things don't go to plan