Nextcloud is not a single "click setup.exe" Windows application.
As I have repeatedly pointed out it is a complex three-tier web application supposed to be run by people with system adminstration experience. You will at least need knowledge in
- networking
- web server operations
- PHP operations
- database operations
if you ever want to run your own Internet facing Nextcloud. If you don't and don't have the resources to learn or someone at hand, why not just rent a turnkey Nextcloud instance from some provider.
Even if you manage to get your instance running - and danb35 did a great amount of work to facilitate that - you absolutely must keep your installation up-to-date with updates. And each and every update requires knowledge in the areas cited above and manual steps on the command line that are not always clear before you start the update but need to be resolved after the fact by an experienced administrator.
I really start to wonder why people who clearly have no idea what they are getting into insist to run that product on premises.
It really is that complex and this is not going away. Running your own Wordpress, TYPO3, Joomla, ... is no different.