I've come to the point of accepting that I will always take notes in multiple formats. Syncing is "achieved" by writing things down in different places enough times that I just eventually remember what I want to do.
I also tend to put different kinds of tasks on different types of lists.
I make little pocket clipboards out of a piece of cedar shingle and a folded-in-half 4x6 brown index card, held together with a mini binder clip. This gives 4 different panels to write on. One of these clipboards is my primary grocery and hardware and other shopping list, which gets the occasional song/band name or funny idea written on it. Another of these lists is for my house and yard projects, using a somewhat bullet-journal like tracking system.
I have a 6x9 wirebound notebook at home that serves as my "daily plan" receptacle for work related tasks (I wfh 3 days a week). I take pictures of these pages if there are any tasks or info I need to refer to at the office. Then when at the office, I have piles of scrap paper that came from mistaken print jobs that I write meeting notes on. Also stickies inevitably get onto both of those. I also have a 4x6 wireboound notebook that fits well in a pocket that I bring when going to other people's work stations to write down the support items that didn't get into the ticket.
Anything that ends up as a project that I will put more time into will get notes written about it in Obsidian, and sometimes still OneNote, and also in the notes text file and comments in the source code of my development projects. I agree that the simple text file is the easiest way to record things on the computer.
As much as I've tried to consolidate these things into one system again and again, my current approach follows the ideas of TFA by just reducing the friction to get something written down somewhere, and if its important enough, in a number of places.
Writing on paper is faster than typing on a phone for me, but not as fast as typing on a PC. But getting to a pen and a blank part of a page is often faster than getting the right note-taking app in focus, so I still tend to mostly do that. Checking something off is also usually more rewarding on paper than on the PC.
And on my grocery lists, I check things off as I put them in the cart, AND cross everything off when done at the store, so that is a double-completion which is extra satisfying!