Tried many things during a long life. In fact, if you are not wedded to the Microsoft platform, than google tasks, calendar, gmail, and docs can combine to a surprisingly good and rather simple solution. But recently I fell in love with obsidian. Perhaps a bit more complicated than some others, at least initially, but also much more flexible and capable. In addition, multi platform (windows, mac, linux, android, ios) and you own your data, kept on your machine, in time proof text format, rather than on some cloud server, that eventually will hold you to ransom. With other systems I have eventually run into a crippling cul-de-sac, in obsidian there always seems to be a way out. Perhaps, it is not so good for teamwork, rather for the lonesome, hyper focussed keyboard worrier. But for them, it rocks.