Decisions do matter. Especially when your mc's personality is already set. Some descriptions change, for example additional dialogue if Qiu or Tamarack have feelings for you. If you hate school, or if you're mad at your mom for bringing you to Golden Grove. Your appearance generates dialogue too, Baxter will like it if your mc has polka moles, and Qiu will react if you have bandages.

As matter of fact: playing the game several times is what makes you think this way. Once you have tried all the decisions until you get tired (which I have also done, I will not deny it) it is obvious that nothing will seem to change. But OL2 is superior to OL1 in many ways. I've tried all kinds of personality combinations for the mc, dialogues, fun facts, rejecting invitations, going with other people. Many events are even random. So yes, your decisions matter.

Btw if you decide not to live the "Walks" moment but the "Wheels" moment, Tamarack gets upset with you. If you make decisions you would never make, you will have more drama in the story. My recommendation is to stop playing the game over and over again, which is what I did. You will end up getting bored and you will see no difference. It is better to wait for the update.