Starting January 4 Google will block sign-ins from embedded browser frameworks

(lists.webkit.org)

But if Google does this properly and uses more sophisticated browser
fingerprinting techniques, Epiphany is done for. This could be an
existential threat for non-Safari WebKit browsers. Nobody is going to
be interested in using a browser that doesn't support Google websites.
Google's expressly-stated goal is to block embedded browser frameworks
and non-supported browsers from signing into Google accounts. The blog
post says: "This block affects CEF-based apps and other non-supported
browsers." It says: "We do not allow sign-in from browsers based on
frameworks like CEF or Embedded Internet Explorer." Clearly CEF is the
main target, but I guess WebKit (and likely also QtWebEngine) is at
risk too; even if we're not mentioned directly, it seems pretty clear
that WebKitGTK, WPE, PlayStation and WinCairo ports, etc. are all
likely non-grata.

Not good at all in terms of the overall health of the web.