Most successful guy I know tried todo apps and didn't find them useful. Mostly used pen and paper notebooks, then partly started using Notion. It's far less rigid than todo apps and doesn't have the same huge maintenance burden. I use it too for the same purpose, and recommend it.
In addition to Reminders.app and a simple Kanban board, writing things down is my goto. Something like Reminders just lessens my mental load (calendar events also work). I don't need to remember what week is recycling or the Tues. night workout class time.
Notion IMO is overhyped. I've tried to use it and really can't stand it. I don't want to build an entire process from scratch. It feels like a tool where people can waste tons of time thinking they are doing something productive. Maybe I'm just not creative enough or I'm too old school.
The Notion setup he showed me wasn't some fancy overengineered "life dashboard", just a pretty basic Kanban board with notes, no fancy process. So it sounds about right.
