It was sad, and it might well be easier if you age together. People change, people get sick, people stop loving one another, regardless of age difference.
At least my grandparents were committed to each other, they stuck it out.
I know this is only an anecdote -- But my father was 26 years older than my mother, and they were very happy together with their three kids until his death.
They used to be incredibly active and loved travelling, and while she was still up for that he could barely move about anymore. He became a grumbly old conservative, out of touch with the world and hostile to everything new.
So she could no longer share her life with him, or have an interesting conversation with her partner.
I just looked through some websites with statistics about the influence of age differences on divorce statistics.
The conclusion of most research is that age differences have little effect on the probability of divorce.