What do you mean? Pinephone is alive and well and you can get your own Linux "toy" for $150. Can't say much about Librem 5, but afaik they are also shipping.
Sailfish is pretty great and I wish them all the best, I did find myself in need of a few features while using it, one thing being their web browsers lack of usb access for devices like yubikeys: https://together.jolla.com/question/213458/usb-2fa-support-i...
I'm just guessing but one reason could be to avoid having to support foreign payment, tax and possibly warranty regimes (Jolla, the company behind Sailfish OS, is based in Finland).
Also they might want to avoid doing business in countries that support software patents and are over litigious over that (eq. USA).
But this limitation is pretty much artificial - the only thing you need to do from the EU is buying the image. This can be achieved via an EU based VPN (reportedly the built in VPN in Opera works) and AFAIK any mainstream payment card will work (does not have to be from an EU country).
Once you got the license and installation image, there are no real EU specific limitations. I have used Sailfish OS twice while on a trip in Japan and all worked just fine - repo access, etc. Also from the download statistics from OpenRepos (a community package repository for Sailfish OS), you can see there is a lot of users from countries that are not officially supported:
No idea, haven't touched WhatsApp and don't intend to. :)
That said, the SW will of course lag behind commercial offerings. Just see how long it took for desktop Linux to catch up to the major players. But open source system gives me the freedom to turn it inside-out, get rid of things I don't want (even systemd if I felt really strongly about it), repair what I want - be the owner of by phone and not just a cow to be milked for rent. Nah, I can live without WhatsApp. Or I can get a secondary cheap Android phone for such apps.
Devices are cheap. If you can't live without certain proprietary apps, carry two phones. If you don't want to do tethering for battery reasons, a second cell plan is under $10/mo.
Alas, all the competitors are now moribund, and much of the market couldn't give two hoots about privacy issues.