I would rather use my phone as the box instead, since it is the device that is potentially on 24/7.

I wish that by installing the app it would take me to the following process:

1. Set up my custom domain preferences 2. Set up email 3. Set up file sharing 4. Set up personal website (optional)

For the periods in which my phone is offline, e.g. on a flight, the whole thing would fall back to the app vendor service as a contingency to people sending me email or wanting to access my website. Once I'm back online, things would be sync up to the phone and the fall back contingency removed.

Maybe it's just me wanting to fast forward the world 5 to 10 years from now.

A phone is not "on" 24/7. A phone is asleep 99% of the time, because anything else would drain the battery too quickly.

Why restrict the software to nextcloud? What if I want Git hosting? Or run some cms. Imo, something like yunohost, arkos or cloudron is better suited.

This, one of the key perks of Sandstorm.io is that you can use apps written in any language that runs on Linux pretty much.

Cloudron.io is fairly similar, though makes some different design choices.

I definitely like sandstorm approach over nextcloud plugin model that tries to make nextcloud do everything. It's a security nightmare

I do too, and I feel Sandstorm has the superior security model of most of these platforms. But a key perk of Nextcloud is that it can be installed on cheap shared hosting which doesn't grant the customer root access.

Sure.

Still, NextCloud provides the most popular cloud stuff for non-techies: Storage like Dropbox and adressbook like Google/Apple.

Do you know how well NextCloud works in a home environment? Is it really easy to automate the punching of a hole in the home firewall to allow access from anywhere? If you know of a project that automates this punching, it's a great combo to nextcloud.

I punched the hole manually. Unfortunately, even this is not enough. The tricky part is to have the same hostname inside and outside of your NAT.