What OSS tools do you use for personal knowledge & task management?

I've been looking into all sorts of them recently: logseq, appflowy, vikunja, etc. What tools do you use? Why? What problems did you run into with the previous set of tools you used for this job?

Right now I'm primarily interested in finding a "zero-knowledge" (cloud provider doesn't have access to my data) system for task management. Needs to be able to have recurring tasks and tasks organized in some interesting/useful ways (by projects/labels/something, maybe a kanban and table view). Deadlines and time tracking/planning interesting but not required.