wolfchild You are well known around here for less than helpful advice. Yes hill climbing to practice hill climbing is great except when you don't have hills and are trying to train regularly and get into better shape to ride them. In some cases very rigid unbending thinking can be fine but sometimes you have to be a bit flexible. Not everyone is going to be exactly like you so sometimes we have to try and meet people where they are at.
Obviously if it is a thread that isn't realistic then you have to be honest and that will lead to more rigid thinking as you espouse but here it is realistic to get into better shape for hill climbing. Sure there is some technique and form for climbing hills but without hills at least getting into better shape and building certain key parts into your workouts can help as much as they can. Maybe imagine yourself as someone who lives in a flat area and hills are hard to find and get to, how would you decide to practice for an event that is far away while still say working and doing your normal life?