Egli, Ella, Essi - we see them sometimes in the multiple choice questions, but they are never used in one of the correct answers. Are these pronouns used at all in normal speech? I have a brief grammar book published 1963 that consistently uses "egli" and "essi."
The only other place I see these is in Biblical passages.
They are obsolete, indeed. They were already obsolete 25 years ago, when I learnt them at the elementary school. Nevertheless, they still teach them to the kids.
However, many people (me.among them) will still stick to egli, ella and essi during an exam at the university, for fear of being considered an ignorant if they use lui, lei and loro.
I thought it's kind-of interesting that Duolingo exposes us to them, but never actually "uses" them. Maybe they just want to get you used to seeing them.
Those pronouns are very rare, when i'm talking about someone i'd say " Lui " instead of " Egli ", it's more normal. For example " Lui è un bravo ragazzo ".
Egli = Lui
Ella = Lei
Essi = Loro
Egli\Ella\Essi are pretty much obsolete, but they're still used in very formal situations. If you're speaking with somebody you can just use Lui\Lei\Loro.
"Esso" (singular "Essi", meaning "it") is an exception, because while not exactly used that often there is no alternative for a singular non-human third person pronoun.
All three are obsolete in speech but not in formal writing, except for ella, that one's just gone (you'll see a few professors of italian that'll get angry at you for using lei instead of ella, but they're all wrong, it's simply not a pronoun that you use anymore).
Egli is on its way out as far as I can tell. You're expected to use it when writing formally but I don't think it really matters. Likewise for essi.
As I thought about each one of the three I could only think of myself using them (essi/egli) in a university exam, so I would have to agree with user kubelnaby. It's good to know they exist because you'll see them, especially if you read a lot of formal stuff, but aside from that they're not really things you should be practicing how to use.
you can find them in formal language or in literature but we don't use them in informal everyday language. when we speak we normally use lui, lei, loro