I'll stick with Signal for now, at least it's something that I can
confidently recommend to people as "WhatsApp, but really
secure/private".
I guess it's a bit more secure/private than whatsapp because you can see
the code of the client, but AFAICT it's still just as centralized :-(
Since it's end-to-end encrypted I fail to see what major benefit
federation would bring for one-to-one communication and small private
groups.
WhatsApp is also (presumably!) end-to-end encrypted, so that's not the
only problem with it.
The problem is also the metadata: it still leaves a centralized record
of who sent what size of message to whom at what time and from which
IP address.