I’m a bit surprised nobody else is missing the option to manage invitees in the Gnome calendar application. I guess it’s not much used professionally maybe.
Not “nobody else”: almost all of us are missing that, but we know that the email+calendaring+addressbooks trio is one of the toughest problems to solve in desktop productivity apps.
I’m using it in a professional setting, but I use Evolution for emails, so my invitations go through that anyway. Those who use other email clients do not have such a workaround.
Is there such an alternative? I mean besides Evolution
The “alternative” is to implement it in GNOME Calendar and whatever may become the alternative email client for GNOME (if Geary is not it). Inventing a third EDS-compatible calendaring app instead of finishing the existing one would be foolish.
See this comment on your other thread for the explanation and links to the relevant tickets.