As a thoroughly casual rider of bicycles, my probably uniformed, knee-jerk opinion is that most people do not need stuff like hydraulic/disc brakes and electronic shifters.
Unless you are a professional racing cyclist, I am super skeptical that any of the marginal gains theoretically offered by this sort of gear is anything that going is going to make a difference, aside from its impact on the cost of your bike and of repairs thereto. And tbh the same goes for carbon frames and suspensions.
All of this sort of gear seems like a way for manufacturers to keep increasing the price, reducing repairability, and pushing vendor lock-in. I know there are people who are really into all of this gear and the theoretical value it offers, but it just seems like another symptom of optimization culture to me.