The format is so easy that anything that can edit txt allows to manage it without hassle, so even if MyFavoriteTool is abandoned in a year, I can continue with my todo system. And synching a text file is a no-brainer too. I now just use dropbox. But used git, rsync and some more in the past.
The only downside I've constantly run against, is that I cannot "share" this with my spouse or colleagues. Guess "team" function could easily be invented, but so far no one has, that I know, and I'm not going to put that task on this todo.txt file either.
This approach is not something that would work for my family...but, maybe i have a friend or 2 (at most!) who could collaborate this way (that is, sharing a text file of ToDos). But, i wonder how annoying it would be to track such a separete file for this? Hmmm. I think at some point the need for multi-person collaboration might break down with only a single text file...and since things likely need to get at least a little more sophisticated, might necesitate more tooling. I guess.
I did only use a text file before fiddling with those two features and finding they did actually help me. Nowadays I use taskwarrior for anything that will last longer than a day, and a temporary text file for only the things I plan to do that day.
While apps might make things easier, unless the individual develops a personal system and follows it in a disciplined fashion, none of these things are going to make a difference.
The question is, whether the form of task keeping the tool encourages fits to your practice. E.g. if you have a well ordered software engineering life, thst thing might be perfect, if you are a mother of three that works as a alpine guide a paper based system might work better. Or you might just not like the choices they made — which is a perfectly fine reason not to use it.
What I have learned is that procrastinators will hunt for the perfect tool to manage their backlog, especially when it means they can avoid tackling their backlog.
One thing tho: time tracking can be an eye opener. Many people do 30 minutes of effective work a day, while (understandably) feeling stressed for not getting shit done. Task Warrior has a great time tracking extension. So depending on your life and needs it might be well worth figuring out where you spend your time.
If you like Command line applications and need something that is good for many tasks in nested projects and time tracking capabilities (e.g. as happens in software world) it is worth checking out.
I spend all day editing in VSCode -- it's nice to use the same tool (and vim keys)