By the way, Fakon browser of KDE is available at Synaptic.
I accidentally found Ubuntu is now using Snapcraft package for installing its supported applications.
I do not use Ubuntu due to several reasons.
Gnome does not support all software under Synaptic Package Manager. For example Opera Browser which I have in my cellphone cannot be installed using Synaptic.
One does not have to go to the terminal.
There is way about it.
Step One
Using Synaptic Package Manager Install Debian Package Installer which is a Graphic installer.
Step Two
Download the Debian package of Opera Browser from Opera Web Site.
Step Three
Open the package using Debian Package installer.
It looks for dependencies and install the package instantly.
If you are not happy using the same one can remove the package.
I used to do this long time ago and I have forgotten the details but with some soul searching reactivate my old habit.
The first Debian package I installed long time ago was AbiWord after many trials.
1. There is a good application launcher called Ulauncher.
It had a Debian package and that is when I decide to try the Debian Package Installer. (Do not confuse with Calamara Installer).
I reinstalled AbiWord and last of all I tried Opera.
I am posting this using Opera browser.
I want to see weather Vivaldi has a Debian package.
Yes, Vivaldi has a Debian package.
These two are Proprietary applications and that is why Debian does not have then in its repository.
That is why I like Debian, it is my choice to look for proprietary applications, if only they oblige with a Debian package.