While Ubuntu Core is mainly used in embedded, IoT, digital signage kiosk setups, software defined switches, industrial, automotive and other use cases with and without GUI, you are right that there is currently no desktop variant of it… but that doesnt mean there are no plans 
in any case this is the real rolling ubuntu…
APT isn’t supported in Ubuntu Core, is it? 
I believe that the system could have two versions: a constantly upgradeable version would be a very nice idea, as long as the LTS version was maintained for those who prefer greater stability, which would be a balance point for the distro. About Ubuntu Core, I only know little about it, but from what I read about it, if it gets a desktop version, it can greatly facilitate the development of new technologies, in order to make people’s lives easier and at the same time, promote cutting-edge innovation.
Not everyone likes the snap system, really.
It takes way more time to load simple applications like the Calculator in Ubuntu when people are using the snap system.
Honestly, I think this issue of Snaps is being an unnecessary fanfare. Obviously everyone here is aware that Snapcraft technology is not mature at the moment, but that is not why everyone is going to leave them alone. The biggest problem for Linux communities today is just that: being afraid of innovation and not accepting the new. I really believe that Canonical will be able to keep Snaps stable, in the meantime, as desktop users, we need to do our part, reporting the bugs to the developers, to finally help Ubuntu to continue implementing the new technologies that emerge, to bring innovation and a safe haven for those who have already given up Windows and MacOS.
But the base system should not use snap, whatever happens.
This probably answers your question:
The speed isn’t good and most users are more familiar with apt. A switch is not acceptable. Also, I’ve read it before.
Actually, it can be. That is, if you use 19.04 or 19.10 or 20.04 devel and going rolling with one of them. If you use 18.04 or the releases before, you won’t get much use out of it, as the root file system structure changed in 19.04.
If you are using Ubuntu 19.10, change repos by
sudo sed -i 's/eoan/devel/g' /etc/apt/sources.list or, if you are using 20.04,
sudo sed -i 's/focal/devel/g' /etc/apt/sources.list
Have look at the folder /usr/share/python-apt/templates. It is full of junk – just ignore them, other than the two files Ubuntu.info and Ubuntu.mirrors. Out of which, you need only the file Ubuntu.info.
If you open the file Ubuntu.info, you’d see that the first entries are under suite: devel and if you go down the file, you’d come to an entry suite: focal. Oh, if you right down to the bottom, you’d find suite: warty.
If you want to change the name, have a look the files in /etc, named issue, issue.net and lsb-release (and also os-release, which is a symlink) and delete the words (development branch) and your installation is always Ubuntu.
When disco was released, and eoan was developing, devel was eoan, when eoan was released, and focal is developing, devel is focal. When, focal will be released, the devel would be next release name repo, and so on. So, if you have devel as your repo, your Ubuntu is rolling, but you are at the mercy of the developers, their successes and failures. But, of course, you can have one or two partitions to play with, and with massive disks these days, you can experiment.
I dispute that, and given the number of 20.04 support requests I see on askubu & like sites, I think evidence does as well too.
I probably don’t have much experience with rolling releases; the box besides me does have opensuse tumbleweed on it, I have another box with debian testing/sid on it and this box uses Ubuntu 20.04 currently (I moved to 20.04 Oct-2019, and I’ve bumped to the development release since 17.10 end of each month of the stable release; ie 17.10 gets released & I bumped to 18.04 in Oct-2017). Late next month this box will make it’s usual bump to 20.10, which to me is as ~equal to debian/opensuse-tumbleweed; so I don’t see a reason for a rolling Ubuntu.
Bumping a release given I do it so early there are almost no changes so rebooting takes as long as the ‘upgrade’ commonly.
I tried installing 20.04 on my laptop and faced a hundred bugs. It would shutdown suddenly. The system would show ‘Problem occurred’ constantly. 
Am following that approach now!! Deleted my old ISO and have got back to work
I think I’ll keep Focal since others aren’t facing issues like me…
Also, I always keep the development releases on my systems, including production. Just in Focal I didn’t because of the issues, but I’ll bear with them.
Will post the ISO once built
Working on it