Chromecast has always had the issue that it's main users are the tech savvy who are comfortable controlling everything via smartphone. That's not a huge percent of the population.
By adding the remote and going for the play of helping you navigate cross app, they seem to be trying to extend out to less savvy users who need a more guided product.
Overall it seems like the longterm plan is to push their subscription services, since I can't imagine they make great money from the devices themselves. Increasing user base is the best way for them to achieve that goal.
While there may be more appliances out there, & some popular ones, they are kind off all off on their own with some random native apps cobbled together out of whatever random sdk the hardware has. The apps almost never coordinate very well with your phone.
Cast is absolutely dominating. Playing a far better game than everyone else. Easy for developers to work with (so easy with the web platform support being built in). Software adoption within a web page makes all the sense & is so easy & flexible. We haven't even seen multi-phone "multiplayer" cast apps get popular but it's easy to do. No one else can compete.
Please let OpenScreenProtocol start getting some traction so we can continue advancing these capabilities & start freely building systems that can work together.
That's not an "hardcore audience" to me. https://www.androidtv-guide.com/
They're distinct ecosystems though because Android TV/Chromecast use the Play Store for content/app delivery, whereas Fire TV/Samsung/Roku use their own respective stores.
If one supported both the Play Store and their own, the definitions might be more subject to question, but as it stands they don't officially allow that.
Pointing out both Android TV and Amazon Fire is Android OS based isn't particularly relevant to market mineshare. Linux too is used by both (and others), but it would be pretty strange to try to combine them all under a "Linux streaming stick" moniker.
I'm sure someone followed instructions they found on Medium and want to show it off to their friends. That's fine. Those aren't the majority of users though.
For half the price of a Chromecast, Android STBs are the 'hit'.
Making it smaller than Samsung, Amazon, and much smaller than Roku (market leader). It seems to have a hardcore audience that think the world of it (or who haven't tried anything else), but most of the market moved on years ago.
If anything this Google TV "Chromecast" is designed to make Chromecast relevant again.