I absolutely think adults, especially parents, ascribe manipulative intent to children when they shouldn't and it's absolutely a problem but it's always kind of funny to me when people go online and proclaim that children are incapable of manipulation. When I was three I asked my mom to get my older sibling their favorite candy bar at the grocery story because I knew she'd get me mine too as a reward for being thoughtful and that was way more likely to succeed than if I just asked for a candy bar for me. And it worked. Children scheme at a developmentally appropriate level the trick is not assuming children scheme at an adult level.
Hi! This is not an example of manipulation, this is an example of a developing understanding of cause and effect, which ultimately is foundational to how EVERYONE makes decisions about their interactions.
It's really commong for people to use the term manipulation to any need-/support-/attendance-meeting behavior where the person does not explicitly say "this is my desired outcome please help me obtain it", but most of those are common and reasonable forms of communication! They may not be EFFECTIVE with every person, because different communication styles may not be complementary with each other. But that doesn't make them bad or immoral or in some way malicious.
The thing is, "manipulative" behavior is typically a term applied to "behavior that I believe I would respond to differently had I known its intended outcome" but that feeling of being "tricked" isn't necessarily something we need to react to. It tends to sit on a spectrum, and while in some cases, we may be briefly annoyed or frustrated, we ultimately weren't harmed or inappropriately restricted, there will be times when the feeling comes from the awareness that we were put in a position that doesn't allow us our no. As with all consent, there is no yes without access to no (and vice versa), and if someone has "been manipulative" by restricting our access to our no, that is harm, regardless of intent.
When people say "children can't be manipulative" what they're typically communicating is "children are rarely (maybe never) empowered to restrict the no of the adults in their lives, meaning their behavior, while potentially not the most effective forms of communication or seeking of need-meeting, this is a teaching opportunity, not a discipline issue." But a lot of people who have spent their lives having any indirect need-meeting method labeled "manipulative" hear it instead as "children can't lie/be passive-aggressive/try to configure their environment and actions in ways that increase the likelihood of the need being successfully met." Unfortunately, these are two very different conversations! So it can be easy for this discussion to turn into people talking past each other due to dual-context verbiage.
Hopefully that helps clarify that you are actually not disagreeing with anything people are saying, even tho it may feel like the language used is mutually exclusive to what you've said here about your context for manipulation
I wasn't seriously disagreeing with the underlying point, I just see posts that stray into "children are too innocent to do this" territory and I wanted to share a funny story about me scheming as a child. Clarification is good though!