Planner notebooks are indeed better than calendars from my own experience. First off, calendars don't have the space to write in detail. With a planner, you can note down the task for each day and write detailed notes, so you can understand any time you flip through.
I am using the Accomplish planner 2023 from Neorah. This life planner helped me stay more productive each day. I make schedules for each month using this planner diary 2023. Unlike a calendar, I can set achievable goals for the month and work on it.
The weekly spread helps me plan more elaborately. When too many assignments or tests have come up, the planner helps me to schedule all of them. I sort out the most important tasks for the week and highlight them in Things to Do, so I don't miss any of the deadlines. This is not possible in case of a calendar, you might miss something important among the numerous notifications you have set.
Planner are travel friendly too. You can slip them in your bag and take them with you everywhere you go, just like your mobile. I also think that using a planner diary is less distracting. It saves me from wandering off into other apps and wasting the time I have.
I also remember things better when I take the time to write them down in my daily planner 2023. The process of writing itself requires some focus, so I would definitely recommend a planner any day, so you can channel that energy into execution.