Hi @ahcheing ,
I get that you are frustrated and would love to see 2 way sync in the mobile apps, yet you also wouldn’t find it in other apps like GDrive, knowing that you rather refer to syncthing and the like. The thing is that while “the community” has been asking for it doesn’t lead to any “right” for having a feature. Nextcloud is an open source project, so anybody from the community is very welcome to implement this and that can also be somebody from Nextcloud as a company of course. Yet as stated the paying customers of Nextcloud as a company never demanded it and customer needs are among other things a priority for the employees. We (since I am also an employee) try our best to balance the needs of customers, the community, technical aspects that should be improved from a development perspective and other stakeholders and aspects.
Building a properly working 2-way sync is not a simple task and having to balance it with the other aspects of our mobile basically led and still leads to this not being a priority but again it is an open source project, so also nobody else from the community ever decided to pick this up in 8 years time. That in a way also tells me that it is really not that needed and not a must (in combination with the above that similar products also don’t have it).
As for what would make you a customer: https://nextcloud.com/pricing/
What puzzles me a bit is that you argue you paid for the Android apps, because the ones published by the company are free, see gplay https://play.google.com/store/apps/developer?id=Nextcloud as well as on f-droid Nextcloud | F-Droid - Free and Open Source Android App Repository and Huawei Gallery https://appgallery.huawei.com/#/app/C102503897 - we do not publish them any place else.
As for Bountysource - that has been dropped by Nextcloud for decisions made by bountysource that conflicted with Nextcloud’s values.