> it seems nobody have tried
Probably because it's too obvious of an idea? And you wouldn't just find people's repos on github with their ledger databases for another obvious reason.
It's like a ton of time to get into such framework, much easier to install some app on your phone. What's the point? (Sincere question)
I had a much more thorough understanding of how my investments were doing as I integrated them into the same ledger files and my total net worth. Which gave me confidence (at one point) to quit a job because I knew exactly how far I could go without income, even accounting for having to buy my own health insurance.
The time investment isn't really that great, and that 40 hours or so was mostly me nerding out with tmux + fswatch to create my own dashboard and a couple other automations that I built to pull down investment and currency data (I had money in a couple currencies for a while there, back down to one ignoring the handful of cryptocurrencies I've acquired over the years which I treat more as investments and not cash anyways). It took me about an hour to get started initially with one ledger file and just going through my accounts for that month (I started near the beginning so entered all transactions back to the 1st to have a complete picture of that month).
It actually became more important when I got married because my wife's attitudes on spending and saving are very different than my own. Seeing how things were going I was able to discuss it dispassionately with her, pointing out things like "You spent $x,xxx on clothing and housewares this month, my income is only $y,yyy and we still have to pay rent. We have savings to cover this, but we need to plan it." She's still a freer spirit with spending than I am, but it's toned down and I didn't come off as angry when I raised the issue, having something to show her (here's what we have, here's what we're spending, here's what we will have in 2 weeks and why we can't buy a house if this pattern continues.) helped a ton. And being able to see that she had only set back things by a month or two in our plans kept me from freaking out when I saw some of those numbers.
I'm not sure it's worth a writeup as anything special, git is (for programmers especially) a conventional way of keeping things synchronized between devices. I also used Dropbox for a time, but I specifically wanted versioning to help keep track of edits and reorgs of my files so I switched to git.