I tried every todo app and ended up with a .txt file

I went through something similar. I do use Logseq now, but for many, many years I found a notes.txt or todo.txt file in my home directory to be an excellent solution. I typically just write the date at the top of the file and put the notes underneath. A huge benefit is that I can trivially keep these under git. I keep them in my dotfiles repo so they can be easily synchronized to all my devices. A couple of shortcuts makes it quite fluid:

A bash alias so I can run `todo` and have the file open:

    alias todo='nvim "$HOME/.todo.txt"'

Some vim config so I can run `\date` (from either insert mode or normal mode) and it will print a date line for me:

    inoremap date =trim(system('date "+%a %B %e, %Y %H:%M:%S %p"'))                                                                                                                                                              
    nnoremap date :put=trim(system('date \"+%a %B %e, %Y %H:%M:%S %p\"'))

things 3 is fantastic and access to it is an actual factor in what devices i buy

I've had a plain TODO.txt file for over 20 years so I agree with all the benefits the author mentioned. However, I don't like it because without an app, there's no runtime loop to notify and alert me of what's coming up.

This means I don't have "ambient awareness" of what's going on unless... I open the TODO.txt file ... manually scan it... then rescan it again and again multiple times per day. It's really tedious and inefficient to manually re-read the same items again. Offloading repetition like that is what computers are good for. I just don't have a good app at the moment to turn my TODO.txt into something I don't have to manually eyeball all the time.

So even though I have a tasks in my TODO.txt, a lot of things still falls through the cracks because I forget I need to do them.

If you have the type of brain that has a built-in "6th sense" of tasks that need to get done, a lightweight-no-runtime TODO.TXT will work fine for you. But it's definitely inadequate for me and I need to fix that.

EDIT replies to "use calendar for reminders" : Yes, that's a workaround but I've resisted doing that because I wanted the utopia of my TODO.TXT file being the Single-Source-Of-Truth instead of manually copying items to Google Calendar. (Yes, I know that "perfection is the enemy of the good" and all that.) The way other people do it is they make Google Calendar itself the SSOT. But that defeats the purpose of the freeform flexibility of the TODO.TXT that has all the notes, etc in addition to tasks.

I want my TODO.TXT to be a unified view of everything I want to do in life and splitting some items off into Google Calendar is just more digital housekeeping I wanted to avoid.

The way I'd prefer to use Google Calendar is via the developer API to programmatically add entries that's based off of my TODO.TXT. E.g. : (https://developers.google.com/workspace/calendar/api/guides/...)

... but that requires an active runtime loop ... like a Python script constantly scanning my TODO.TXT and then automatically populating the Google Calendar. I just haven't gotten around to coding that yet. Yes, the irony is that meta-task to enhance my TODO.txt is already in my TODO.txt.

I’ve never found a productivity tool/to-do list app I use more than just sending myself a barely comprehensible email.

This flies a bit in the face of the author's "The sync breaks. The company sells out and dies" point and the simple beauty of a text file. I find that Obsidian.md is just one step above a text file.

Simple daily notes, which are automatically organized into year and month folders. (Tip: Set the date format to YYYY/YYYY-MM/YYYY-MM-DD)

The Sync feature works great, but no reason you couldn't do this with just git on your own.

Plenty of built-in features (Plugins, ToDos, etc...)

Cross platform apps.

Markdown

Free. The sync feature is $4/month. Worth it for me.

They also have a one-time $25 payment to get early access to beta versions and a VIP discord channel.