@5128gap
Some older men want younger women specifically for their youth, for all the reasons already mentioned. But ime most want a physically attractive woman and that is higher priority than age. The physical characteristics men commonly find attractive are more frequently found in younger women, so this tends to appear to be a preference for youth, but where an older woman has them and a younger one doesn't, the older one will generally be preferred. I often socialise in groups of women age mid 20s to 50s and see this happen a lot.
But I wonder (as I said earlier on,) why men in their 40s and 50s seem to think that they are so sexy and hot and desirable, that they can easily snare a woman 15-20 years younger, but they think that
women in their own age group are repugnant?
I also agree with @Soso7 that many men want slim women - preferably thin/underweight, (even if their previous partner/wife was fat.) And they often don't care what her face is like - OR her personality, as long as she is thin.
I have met many a man - including an old boss, my BFF's brother, and an older cousin of mine, who prefer a thin woman - not slim, or athletic, or even curvy, just THIN, or even skinny. They don't care what their face is like, OR their personality, as long as they're thin/skinny.