I am also using iOS with Möbius Sync and it is working quite well. The sync is not running all the time in the background due to iOS restrictions but it is running multiple times per day on my device.
The option to sync folders was only introduced this year. It costs about 5$ one time payment.
There will be many conversion tools for Joplin to other structures. So I guess the format is a non issue.
But how high is the rate of unemployment in your country? In Germany it is really low, so it probably costs a working person only a few euros per month to support all children of unemployed persons. Not sure if it is worth it to not help these children as they are already severely disadvantaged. Not to mention it can be seen as an investment in these children.
Have you calculated how much money goes to these children of non-working people?
If you are not paying for Sync you are getting ads. So you are still paying (attention, data, you are the product).
Additionally proprietary software has some long term disadvantages that are not visible at first. This is why one needs to always inform people about it as they do not understand these disadvantages.
The biggest issue is that the owners of the proprietary code can change its course whenever they like it. See for example the Reddit Apollo Dev who would have sold out the community for 10 million dollars:
See his own published audio and the discussion on HN:
https://christianselig.com/apollo-end/reddit-third-call-may-31-end.m4a
Would you say that the average citizen of a developed nation is one of these rich or is benefiting from the rich? They probably make up the most of these statistics about happiness.
iOS has Möbius Sync as a Syncthing client, but it is not free ( but only 5$ one time payment) if you want to sync folders from other apps like Syncthing. The option to sync other folders was introduced this year.