I love NextCloud! It's a bit much if all you need is tasks, since it was created as more of a "replace all things Google" type solution. You can also host it on a VPS if you don't have hardware to put it on and keep running 24/7, too.
Discussion
I have 2 Nostr relays so I think one next cloud in the house will not be one issue. But I don't think next cloud will one good task tool for me. I need some other possibilities. I will try to write a document about it