At least until the official client allows registration from desktop without VM shenanigans, and allows an arbitrary SOCKS proxy instead of just their own, and doesn’t depend on Google services on mobile, there NEED to be third-party clients like signal-cli or Molly.
“Rabbit hole”? Isn’t it as easy as just not going to a carrier’s store for it?
We always bought from generic tech stores, almost always big chain ones - never got a carrier-locked device. Is it different in the US?