Don't get my wrong : the "WTF Internet ?!" insulting part was toward the youtubers' obsession with stalking significant others on ground of paranoia.
Definitely not to you.

I think you have every right to hate Sailfish X personnally (every one has different tastest) and if indeed WhatsApp is the only thing holding you back from going back to your previous smartphone, the web.whatsapp.com webapp looks like a valid solution to me.
(It was initially geared toward desktop users to address the lack of native desktop clients, but could adresse any machine with no native client and a decent browser).