Those pta example files you linked, marttt, really make the case for this software. It looks simple, transparent, auditable, versionable and unixy.
Dpifke, beancounter looks nice, big and well tought out. I bookmarked the docs/ to have a more troughout look at it later.
Update: Had a more detailed look on Beancount.
pta, however, does this numbering [2], so for filing taxes in my country, its journal format seems more straightforward in case auditors should have any interest in it. I also quite like its terseness (1 transaction = often 1 line, as compared to 3 in a ledger-cli journal -- gives a better overview and is somewhat better to parse further with sed or awk when needed [3]). Finally, it is a single Perl script, thus very portable and lightweight.
All that said, pta doesn't seem to have much of a following, as compared to ledger-cli, which, obviously, is a much more mature project.
There was also an interesting discussion regarding pta vs ledger, involving the author, OpenBSD dev Ingo Schwarze [4] -- well worth a read regarding the general plain text accounting philosophy also. Interesting stuff.
1: https://mandoc.bsd.lv/pta/
2: https://cvsweb.bsd.lv/pta/accounts.example.en?rev=1.3&conten...
3: https://cvsweb.bsd.lv/~checkout~/pta/journal.example.en?rev=...
4: https://www.undeadly.org/cgi?action=article;sid=202009281234...