Why do older men hit on younger women ?

Just curious to know. So my bestie looks very young, like late teens or early twenties, she's short 5'1, really very cute, too pretty, gives off a very cute vibe and she seems like a young pretty kid unlike other ladies of my age. She gets hit by a lot of men, who are much older, and often very unsolicited, lustful and creepy, who say ridiculous misogynistic things. I have experienced similar things and creepy lustful intent from older men when I was in late teens, who would say I'm more mature than people of my age( I was obviously not), fresh, youthful and make them feel younger because they like being around young people. Altho all of this has stopped once I became a proper adult, most men do not hit like this or atleast don't show their intentions. I have seen this a lot, both with myself and bestie, some people shamelessly hit on 20 years younger women and gaslight them, which is concerning and disturbing. So do men really hit on young or younger looking women solely for sexual gratification and also it's so disgusting to see fetishize like that and isn't it just predatory? It's just shocking to see older men being more involved in all this, actually put out this disgusting behaviour, go head over heels and groom young girls? Why do they do this ? Is it a fetish or something ? ( Not all men ofcourse) And this is getting common nowadays