F-Droid version.

Tried to install it on Android, stuck at “Starting Sable” forever.

If this is so good, why is it the first time I see it?

What’s the catch?

Yes.

For which major OS there’s no XMPP client?

It’s not like I want to argue, generally curious. What does Excel do that Calc doesn’t?

I work with text a lot, so I’m good with Writer (or Word), but I rarely do anything advanced in Calc or Excel, for basic stuff Calc is fine. I really don’t know enough to compare the two.

their preferred office suite

Usually it’s not “their preferred office suite” but “office suite they are forces to use at work”. MS Office usage is high because of network effect, not because any other office suite is worse.

I use LO Writer for any document I write (or work with) myself and it’s perfectly fine. The only reason I keep MS Office is that I need to work on documents other people write (or need to work with).

Of course there are people who actually prefer MS Office, but it’s similar to Windows itself: most people did not choose it, they either don’t know there is an alternative or are forced to use it for compatibility reasons (at work). It’s rare that anyone actually “prefers” MS software.