The most consequential thing about prayer is not what it asks for but that it recurs. A religion that fixes prayer times has taken possession of its adherents' days, and that is a larger claim on a life than any doctrine.
Islam is the clearest case. The five prayers are tied to solar positions, so the schedule shifts through the year and differs by latitude, and in high northern summers jurists have had to rule on what to do where night barely falls. The call to prayer sets the acoustic character of a Muslim city. Employers, airlines, hospitals and armies accommodate it, and where they decline to, it becomes a matter for the courts.
Judaism fixes three services and attaches short blessings to a great many ordinary acts, so that the day is punctuated by formulas rather than only by services. Christian monasticism built an entire architecture of time: the offices, the bell, the rising in the dark. It shaped European timekeeping itself, and the mechanical clock was developed in part to wake monks reliably.
There is a comparative point here that resists the usual framing. Fixed prayer is often described as a burden that sincerity lightens, but practitioners across these traditions describe the opposite relation: the schedule is what carries them when sincerity is absent, and the days it is hardest to pray are held to be the days it matters most. It works in the way a rule of exercise works. This is why the traditions that keep it are entirely unembarrassed about the mechanical quality of the obligation, and why converts often report the schedule, rather than the belief, as the thing that changed their life.