This is more for information for people, after having been frustrated by this issue.
It is possible to connect newer soundbars to newer TV's and do away with the HDMI cable but keep high quality audio and full Alexa control (or Google, or neither if you don't use your soundcard as a smart speaker).
The only, and big problem, is that this currently only works for YouTube and not for the other smart TV apps (e.g. Netflix, Prime, iPlayer, etc.). I have been told that this feature will be added relatively soon, maybe a few months.
Please don't hold your breath, but do feel free to complain.