How often do your older cats play?
When you get a kitten you can spend hours playing with them. I have often seen clients that have a vast array of toys strewn over the floor that their cat 'used to' play with but no longer does.
I wonder if this is because the kitten grew into a more independent cat who made their own entertainment elsewhere or if the owners grew bored of making the extra effort once the kitten period ended. For most cat owners its probably a combination of both. Cats often have a favorite game that they like to engage with. One of my cats will only play with string, another with sponge little footballs, another with catnip toys and my last just wants human interaction and plays fetch. They will also play together and with each other which is lovely to see.
Now they are much older, oldest being 10 yrs their love of play is still there and more importantly keeps them happy and healthy. Play is a great way of not only engaging with our pets but as a way of monitoring how they move to see if there are any signs of early mobility issues such as arthritis. Cats that may have been agile with jumping and pouncing may not display such behaviour ranges during older age. They may still want to play but change the way they play with you. If you notice a change in the way your cat moves it would be work getting them checked with the vet for an assessment as arthritis can be helped and there is not need for them to suffer with discomfort.
Top tip, the best way to assess cats behaviour over a longer range time period is to video how they move every 6 months and reassess to see if the way they move is changing. We all want to believe our pets are as mobile as they ever have been but this is a good way to really double check.