In getting started it does give the table names... which are all prefixed cd.tablename, it is an educational tool so one would expect one to read the getting started pages first.
There are different types of learner, some learn by poking stuff with a stick rather than meticulously reading everything.
I have no idea about postgre as I know SQL Server & MySQL, I was actually having a quick go to see if my knowledge easily translated.
But schemas are a YAGNI 99% of the time feature in those.
What? I literally have only ever written one web app that didn't use multiple schemas, and that was a simple blog. I think you are confusing "I don't bother to use X" with "X isn't very useful".
There's little to no chance of collisions but you have to use them constantly, which is annoying. Few benefits, lots of downsides.
Obviously this only becomes super-useful in pretty sizeable projects, but I tend to consider using schemas a good habit to be in.
This is the opposite of how it should be. You'd expect learners to be less likely to read a "getting started" page than an expert.
For example, saying to a beginner, "Oh, the tables are all prefixed with cd.tablename" will likely result in a look of confusion because the beginner didn't understand any of the words you used or the way in which you combined them. Is that period special, for example? You said prefix, so if I type "cd.tablenamefacilities" will that work? What are tables and how do I know what their "name" is? Why is the error message talking about "relations?" And so on.