I was looking at tasks.org and it seems pretty nice. I think I have two types of tasks usually. Some are more project oriented and fit better with a trello style kanban board, but I also have simpler ones like grocery lists, bill reminders, etc. I use remember the milk for that currently, but I’ll probably try switching.
I was also looking at etesync recently for caldav/cardav but I kind of like the idea of it being integrated into nextcloud better.