@Klif
I've been struggling with this for 30 years. Physical notebooks, apps, platforms, you name it.
Trello was the best contender for a long time but it enshittified and its too specific to tasks>lists>boards, sometimes I need to free form.
Past year or so I've been self-hosting #silverbullet. Browser based markdown OneNote / Obsidian equivalent - fewer features than those but dirt simple, reliable and programmable/extensible/scriptable. If I have a device, I have my notes. And the self-hosting is rather nice.
Downside, unlike some other apps/platforms if something has a due date or needs a reminder, silverbullet doesn't come with that or notifications out of box (Im sure one could script something)
No matter what I choose though, I find I have to discipline myself to periodically go and refresh and update and prune. Otherwise lists get too long --> ugh this list ill never finish -> start new list -> repeat.