I got a better answer just by reading a definition of manipulation:

to change by deceptive or unfair means so as to serve one’s purpose

It is as much about the means as it is about the purpose. So if you are manipulating a kid so they behave in a way that will help him get throug life this is not manipulation. But if you manipulate them into something that only serves you… Yeah that is manipulation.

So in case of convincing someone in a debate it depends. If you goal is to win a debate by manipulation, so you can feel as a winner, that is manipulation. But if you want yo educate them this is not.

I would also like to hear other people persoective on that.

Because obvious answer would be to convince them on subconscious level instead by directly convincind them.

But a mere praise can often change someone interest and even values.

It gets even trickier if we are talking about raising a kid. You actually want them to adopt your values etc… You are supposed to praise the behaviour you want. Especially if they are to small to understand reasoning. And you fully understand you are completely shapping their personality on a level they do not understand.

So I do not know. Maybe all of that is manipulation but not all manipulation is bad?