It sounds like you just hate feminine stuff. One of the main protagonists is a girl that enjoys being girly. Just because you find that boring and unrelatable doesn't mean that everyone does. Plus, Mabel's quest for love often did get her involved with more benign supernatural elements like a cloned boy band, gnomes, a child psychic, a merman, and a disillusioned cupid. Not to mention some of her other nonromantic adventures involving unicorns, golf people, and dinosaurs.
Dipper also often became involved with the supernatural, not because he sought it out in interest, but because he was trying to solve his mundane problems of the day like getting beat up by a teenager, or obsessing about his hight, or trying to win the affection of Wendy, and the supernatural just happened to get involved.>What, you mean generate an actual plot with more potentials and tensions than just “Mabel didn’t get to pump up her ego?"
Ironic that you should say that since out of all the main characters, Dipper is the one the ones that contributed least to the central plot of the show. Ford, Bill, Gideon, Stan, and Mabel all had character arcs and made major decisions that affected the main plot. Dipper, on the other hand, was as much a tag-along to all these major events and Wendy and Soos were. True, he was super into all the little happenings going on around town, but those rarely if ever tied into the main mystery. The most he ever contributed to the central story was that small scene of showing Stan journal #3 so that Stan could actually kick off the plot, and that's about it.
Heck, you could literally remove him entirely from the last episode of the show, and nothing would change event wise. The town working together created the mech, Mabel blinded Bill which allowed her and Dipper to escape and stall him by forcing him to chase them around, and Stan and Ford were the ones who pulled off the switch that allowed them to finish Bill off. Dipper was superfluous.