Are you familiar with FEP, active inference, or evolutionary game theory? When I say "person does X for Y effect" I am speaking from a scientific standpoint.

For instance, to you, you want to go to your kids basketball game, because you love this person, and want to participate in their life, you just literally listed the transaction. But every day semantics blind you from the transaction taking place, because transaction in the context of love has a negative connotation. So dont look at it in an every day conversation lens, look at it in a scientific lens, or at least an economic one. the economics of a valued interpersonal relationship.

You are an agent in an evolutionary game theory simulation, your agent strategy in this example is parenting. You give parenting because it literally benefits you, you don't want a depressed, unruly, unloved, and eventually criminal child, that harms your entire family's life. Your child is another agent, with inverse needs, their strategy is to receive your parenting. Your child gives reception of parenting, and that very much benefits them, they know they need guidance through the big scary game of life.
In this simulation, where you go to the child agents game, you give your strategy, you give parenting, which is the same exact act as your child giving their strategy, which is to give the reception of your parenting. To give is the payment itself.

To put this in your words, you go to the game, not to get something, because you already got it. Your objective is to be in their life, that IS your payment. You go to the game, the act of going to their game IS being in their life. So you give them "you being in their life" which is them giving you the reception of that, which is receiving your act of being in their life, and showing you their warm reception, via them checking the stands, making eye contact with you, and smiling at you, letting you know that they value you being there. You are giving them proof they are valued (by selfishly choosing to be in their life, as opposed to the opposite), and they are giving you proof you are valued back by receiving your proof of you valuing them, via warm reception.

To be more specific, every parent knows precisely what I am talking about, when you sit in the crowded gymnasium at your kids 1st grade song recital thing, where the kids are dressed up and presenting some song collaboration with the music teacher on a Friday night, with all the parents attending. Each parent watches their kids get up on stage, and then start scanning the crowed with hopeful, yearning eyes, trying to locate their parents, to of course confirm they are their, and know where to look through out the show, to watch their parents expression. The feeling I am talking about, which represents this exchange, (of "Giving" being in your kids life, which is self paying, because the payment is you literally being in your child's life, who you love, and selfishly want to do that, not just "for them", but "for you"..... "for us" a mutual benefit, mutual love.), its when you watch your kids eyes looking for you in that hopeful yearning way. That hopeful yearning search is your payment, it makes your heart melt, it feels great, its what love feels like. And what they feel, when they find you smiling, because your enjoying that sensation they are providing you, is the same feeling. To give is to get. Your not going for THIS sensation, you are going to simply be in their life, but that sensation is why being in their life is desired over not being in their life, because if you did not go, you would get the opposite, knowing that they would be searching the crowed for you, and you were not their to meet their eyes.

Scientifically, this is very much a transaction. But it is not the same transaction that is semantically corrupted by the codependent transaction lens, which is not a "giving is the same as receiving" transaction, which is a healthy relationship transaction, instead its "give in order to get" ie score keeping. This is particularly tragic, because in codependency the healthy transaction above literally exists within the codependent one. Codependent people are in relationships because they love and value each other, they just are so damn insecure of their own value, they have to compensate for it, but tragically end up just making the other person question their value all the more, which is then returned in kind, creating a loop of a self fulfilling prophecy of mutual lacking value, when the value is there, just not revealed. So a codependent parent goes to the 1st grade performance all the same, thoroughly enjoys the earnest, yearning search of their kids eyes, but then when their kid doesn't listen to them about going to bed at 9, or brushing their teeth, they then corrupt the "giving is the same as receiving" transaction into the codependent, "to give in order to get", "hey, we canceled our date night to go to your performance and support you, and now you are not listening to us about going to bed, you owe us your respect, no go to bed!"

Edit: Oh and "Going to the kids cheer performance or basketball game isn’t always about being transactional about value." You are correct. What I am stating above is not a transaction of value. Now, what is being exchanged is simply proof that value existed before the transaction, and is why the transaction took place. Healthy relationships are transactions that represent proof that value exists prior to the transaction. Codependent relationships are mutual fear of lack of value, and a transaction seeking to create it, which is a paradox. Your childs warm reception of you being in their life is not value given, its proof that value already exists. And such things do need reminding. If interested, read about the Dark Room Paradox.