I had a similar need and settled on tasks.org. Depending on your needs, this may not fit. It's more of a Google/Microsoft tasks replacement. It's been really nice for my needs.
In what format are tasks saved?
Edit: after a bit of poking around I can see that the exports at least are json.
Yeah, I'm not sure TBH. I have it sync with my Nextcloud instance. Within the web browser it shows up in the Nextcloud Tasks app
Orgzly Revived deleted every list/note app I tried.
Heavy plus. Especially due to the fact, that the app stores notes/todos as a plain human-readable text (org-mode format), no proprietary formats or vendor-lock to the app.
That comment led me on the wildest journey of org-mode discovery that you can imagine 🤣
It'd be helpful to learn more about your requirements. Does it need to be open source? Any must-have features? Native apps? Etc.
I've been preparing to make the leap to Vikunja in an effort to go self hosted. I can't tell you how it is yet, but it may be worth looking into.
TickTick may fit your needs?
I switched over to TickTick when Todoist suddenly changed their pricing model a few years ago. I don't remember the specifics of what happened but I remember being very frustrated with the sudden changes as it would've required me to change my whole system.
I've been very happy with TickTick since then and would strongly recommend OP checks it out to see if it fits their needs.
Not sure if a Chinese app will offer more privacy.
Fair assessment, official company headquarters based in California but a lot of Chinese devs as well as the owner. Good to be aware of.
I've been using SuperProductivity and it's been pretty good
Been using Legendapp for about 2 years now - it's great except the android app is not great. Worth giving it a try at least I'll say.
I've just deployed a self hosted vikunja server for my work team. I'm trying it right now. So far it looks pretty well. You can add tasks, group them into projects and establish relationships between them. I recoomend to give it a chance. https://vikunja.io/
Privacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy.
In this community everyone is welcome to post links and discuss topics related to privacy.
much thanks to @gary_host_laptop for the logo design :)