I think you're missing the point. In this case it being a website is an awesome thing.
The underlying tech is powered by the WebSerial protocol. We basically already have the executable you're asking for. As long as Google supplies the firmware blob (and js source, though this can probably just be ripped from the current web page), anyone will be able to put up a server, and anyone with a modern browser will be able to visit the site and update -- without having to install anything locally.
Given that a 'native' app would probably be some bloated Electron abomination, I was actually pleasantly surprised that Google chose to solve the firmware update problem the way they did; it worked flawlessly for me on Linux which is seldom the case when it comes to these things.
It's hilarious to me you're glad it's not a bloated Electron abomination while also taking about the joys of it requiring a whole web browser to operate.
and you require a whole OS. I expect browsers to outlast OSes. Browsers ran on MacOS 9 and software that ran on those browsers still runs today. MacOS 9 itself, not so much
I've used a lot of old web applications which require some ancient web browser (especially IE) or old version of CGI or PHP to properly be hosted or require some browser plugin that is no longer supported. The idea that it'll continue to work just because it's "web" is once again absolutely hilarious to me. Just wait another five years and all the WebUSB protocols this relies on get reinvented and this gets considered unsafe and deprecated.
And sure, when talking about an OS that's often made a point at cutting off support for old binaries it's not good. You're ignoring the fact I can still run a lot of 30+ year old software on modern Linux and often modern Windows with ease.
The underlying tech is powered by the WebSerial protocol. We basically already have the executable you're asking for. As long as Google supplies the firmware blob (and js source, though this can probably just be ripped from the current web page), anyone will be able to put up a server, and anyone with a modern browser will be able to visit the site and update -- without having to install anything locally.
Given that a 'native' app would probably be some bloated Electron abomination, I was actually pleasantly surprised that Google chose to solve the firmware update problem the way they did; it worked flawlessly for me on Linux which is seldom the case when it comes to these things.