Maybe not for you, but others would beg to differ?
Darwin apparently had debilitating illnesses at 72 (one year before his death) when he published a book on earthworms and their role in forming soil. And Pasteur was apparently paralyzed at 63 when he developed the rabies vaccine. Etc.
Should they have just kicked the bucket when they lost their health, because of the pointlessness of living past that?
That doesn't mean those already I'll should just give up, it means those looking to their future should consider whether living 20 more healthy years is better than living 40 more years if 30 of those are increasingly focused on just treating symptoms to wake up tomorrow.
We can all come up with shitty anecdotes.
Canada has medical assistance in dying now that lets people avoid this.