For a moment, I thought there was something wrong with the Chromecast with Google TV, but I was not better informed after reading this article. Is it missing some important codec for video or audio? Is the audio output limited in some way? Is it slow?
I admit that I have mine connected to an 8 year old midrange TV that doesn't have a surround sound system, so it's fair to say I haven't pushed it hard, but there's very little that needs to change on the Google TV stick. They don't need to make a clone of the Apple TV, nor does it need to become a smart speaker -- Google has many affordable options, all of which can cast to your Google TV stick.
If I were to ask for a change, I would like dedicated media control buttons on the remove, backlighting, and on the software side, an ambient screen mode that one can use to display a webpage that has my calendar and TODO lists.
I don't feel the device is sluggish, so I won't ask for a faster chipset just for kicks. Anyone who jas Wifi 5 or better with a 5ghz access point really doesn't need ethernet. Google's analytics actually probably indicate this. Almost nobody other than hardcore enthusiasts bother to use ethernet, and it makes even less sense on a streaming stick that tops out 25mbps of bandwidth to work flawlessly.
Upgrade your home wifi if you're struggling. You can find several very good Wifi 5 routers on ebay for £50 or less, including mesh systems.