I highly recommend Nextcloud. It started as a FOSS Dropbox clone, but they have since implemented easily installable server plugins (which they call "apps") that allow your personal Nextcloud server to fill the role of many other SaaS products.
It's taking up just under 200Mb on my server, with most of that allocated to the MySQL daemon. I have noticed page loading can be pretty slow. No idea why since the CPU monitor never goes above 10%.
I'd guess easy hostability would be the main one, not anything technical. More hosting companies support PHP than any other language, and using it means people can set up their own file sharing system without needing to know much about server management.
That's arguably the reason most popular CMS systems run PHP too; because they'd rather have something that's easier to setup and can be run nearly anywhere than something that requires knowing how to use a terminal or something.
I don't think shared hosting is dead. It's less popular among startups and tech savvy companies than it used too be, but there are still tons of companies and individuals who use it. Companies like GoDaddy and EIG still make a ton of money (even if many would rather they didn't), and many agencies specialising in WordPress/Magento/Drupal/whatever still get a lot of business.
I would be OK with both those, but not distributing packages for CentOS and mingling configuration with program data (You can't just untar the release into your installation location, that will overwrite your local configuration) are the dealbreakers.
It's a nightmare to maintain keep updated (manual processes galore), but it has a fast release cadence. The worst of both worlds.
For me, the functionality is only 20% if the value, people spending time making sure those services are running well 24 hours a day all year round is 80% of the value.
Just make that you have backups of your data, it's one thing to be deprived of services for x days, but a completely different thing to lose data forever.
I've been working on a prototype that lets you run self-hosted applications on a server which are then accessed through your web browser. I've been looking forward to incorporating applications that are on the awesome selfhosted list. Code here: https://github.com/cloud-computer/cloud-computer
Sandstorm requires that the web apps are packaged specifically for it. The process is not hard, but you have to decide to do it. Sadly, most apps that have been packaged have not been kept up to date.
That said, it's a great platform. I have customers using it with some marketplace apps and some custom apps. My only wish is that more people used and developed for it.
I had a sandstorm instance for a while, but stopped using it due to the dwindling community. There are some alternatives now, but the best part about Sandstorm in particular was the small atomic backups for each Web app you had. I haven't seen other system try to abstract above the applications like that...
Sandstorm was really ahead of its time. This is a super hard thing to know, but if what you are doing resonates with too small of a population it will take a long time become popular.
I could have seen it be a great software dimension to home routers and NAS boxes.
Pretty cool, but anytime I see something promoting Debian anymore, I can't help but think it is probably outdated and cumbersome to create and manage packages, especially compared to Arch or Alpine, and definitely more bloated than Alpine.
I've been using Debian for more than 15 years and it has always been about stability. I use it for desktop use (office, mail, web, games). In the past, the stability concern meant, indeed, sub par desktop software but since the last two releases, the desktop is really good and stable. As I'm getting older I don't want to spend my time administering a system and Debian (and all its packages) have now reached a very good maturity level. Sure it's not bleeding edge, but the stable baseline is really good new.
(and my PC is now ten years old).
So don't judge too fast. Debian does a really good job now, even for desktop usage.
Arch isn't bleeding edge either. It has always been stable for me and extremely easy to administer, but I have the benefit of actually having the true latest stable packages that you consider bleeding edge, but they are in fact stable just like they are called when they are released.
Bleeding edge has never been the point of Debian, it's one of the most stable and well tested distros out there. Things are upgraded only when necessary for the most part.
https://apps.nextcloud.com/