Because what Google wants to buy is their marketshare and existing userbase. I very much doubt fitbit has any tech or products google couldn't make themselves in a few months. The longer fitbit sucks compared to their competition the lower that becomes.
Google would have absolutely no issue creating quality fitbit devices. Whether or not the market would be there for them to stay in long term, I don't know.
Or those wonderful Android Watches, sorry wearOS, never mind, they aren't getting proper updates for ages now.
The Chromecast works well most of the time. The ways it fails is ridiculous.
EDIT - never mind, Asus made both of those
Asus did make both, but I'm not sure either was as good as you recall, sadly.
Seems to be a finished-ish enterprise product now.
Hard to continue developing a product when the most talented people in the company have gone elsewhere already. They need the human capital in order to make sure it stays afloat and they get the requisite knowledge transfer.
Then its anybody's guess what will happen. Google's track record of buying technology and then doing something better with it is not encouraging at all.
Err...what? Earth, Maps, Docs, Waymo, Android, YouTube, WebRTC, Flights, Deepmind all come from acquisitions.[1]
1. https://en.wikipedia.org/wiki/List_of_mergers_and_acquisitio...
Personally, I'm curious how that worked out for them. The announcement of this purchase, and how they handled Nest, is what made me stop using my Fitbit.
Considering how absolutely dreadful Google's hardware (pixel line, pixel watch) is nowadays, and how unfinished all of their software is, no, Google would not be able to make any of that in a few months.