Why do older people like to pick on younger people?

Why do older people like to pick on younger people? Like older adults will call younger adults kiddo when they aren’t kids but adults. Are older people jealous and bitter that the younger people get more job opportunities and are visually more attractive? Also younger people are the future and it should be the older people’s job to take care and groom the younger people for success just like they do in family businesses or certain jobs.

You may have raised some valid points & hit them on the head. Also, some just do it out of habit, or because it's something they've always done, like from the time of growing up & in school. So they call the younger people than them - that. Sometimes, too, it is a form of endearment, I feel. At least that's how it (can) come across when people more my mom & dad's age, or generation, say it. So I do believe that context can matter. But I'd try not to take it too much to heart. As there can be times when it is meant as a put-down. Or a slight. However, there are also times when it is not that, the opposite in fact, or more benign in nature~

I sometimes call people/friends my own age, "Kiddo." And boy, do they ever take notice!

In my case: I intend it to be, or mean, as a nice gesture. Though they don't always receive or interpret it that way...

tone can be a mysterious thing to judge at times; but if you're able to (detect it - from them). Then that may help and go a long way in deciphering their meaning, and their intent(ions). :^)

Though I'll admit, sometimes it can be hard to tell especially if they are being mercurial.

I think it depends on the intentions of the person speaking and also how we perceive it. Some of us may have issues with being called "kiddo" if people in the past have considered us irresponsible and child-like, and so those feelings might come back, and we might take them out on someone who doesn't really mean to hurt us. But that's just one perspective. If the person truly feels like they are superior to us in some way by saying "kiddo", that's different. But I personally don't like that word, even when it's said to children. I think it's a bit demeaning. And I surely don't like hearing it from friends my own age.

And younger people do the same to older people
Boomer this, boomer that

I admit to calling younger people "kiddo", but only those I know, who know me and my intent.
I offer it as a gentle, slightly affectionate alternative to "Hey, you" and they don't seem to mind,
I can see how strangers might be offended, but I don't use casual terms of endearment to them
Just my take on it

peace