You can do su to change the user in the current shell. Afaik it just defaults to root if no user ist specified. Everytime you run su you actually do su root
That said I always thought that it stands for switch user so intereresting to know that it‘s substitute.
Also miss it. I took a couple of years to warm up to it. Then when started to I really really like it, it went downwards.
I‘ve actually stopped using Unity a few month before Canonical abandoned it because with all the Gnome applications moving into a completly different direction it didn‘t feel consistent at all anymore.
In information technologies there are three main security goals: Confidentiality, Integrity, Availability. And while Signal is really good with the first two it utterly fails with the last one (at least on iOS).
Still I use Signal every day and would also recommend it to everybody who just wants a good private instant messaging client. While I also like and use Matrix (and see a bright future for the protocoll) there are still far too many problems to use it stress-free and smothly in everyday life.
I still use my Pinebook Pro as daily driver (next to a desktop pc) and I‘m actually quit happy with it. It’s not the most powefull machine but it does it‘s job.
Also I never really experimented with all the special distros. Nowadays I just run plane Debian on it and everything seems fine.