"Preparing a person for a position requiring skilled behavior, especially by providing opportunity for practise and guidance in making the right decisions." Now id like to see how knowing a person is the same as preparing the person, in this case, for a sexual relationship. The act of grooming minors entails to prepare them for sexual acts in order for the abuser to have a willing object for their sexual gratification.

What you are having a problem with, and i would even say rightfully so, is the power imbalance between these people. Power imbalance can have many sources, lika age gap, power or wealth. Not sure which is the biggest factor here. But again, calling it grooming simply is the worst way to adress the problem you actually want to talk about and it is hurting victims of actual grooming. Just like calling the GOP a bunch of groomers when you would need to adress the corruption and their obvious steps towards dismantling the democracy. It is helping the offenders by derailing the whole conversation without offering any actionable steps.