We had more than 380,000 DAU (Daily Active Users) from 36 countries with all good feedbacks on Google Chrome Web Store, but even so, Google always tried to find a way to get us delisted and sometimes removed... they called it "an automated review process that is not performed by humans".
Every time this happened we need to send several messages to all available email address to get our extension approved and listed again in 24-48 hours. After facing this kind of situation more than 12 times, we simply gave up and remembered that it's not worth trying to build a business (or App) on top 3rd party company, like Google or FB.
Google doesn't have much incentive to make it easy, but third parties (like Debian) do, and do a lot of the heavy lifting on an ongoing basis.
I have Chromium installed on a my Ubuntu desktop but I think I had to add a PPA to get it.
Most of the more-or-less mainstream distros ship Chromium in their standard repos. In fact, they're more likely to ship Chromium than Chrome due to the fact that the former is FOSS and the latter is not.
Neither macOS nor Windows have such a philosophy of "prioritize the FOSS alternative", so Chrome is unsurprisingly the better-supported option there.
That's actually how I first started using Chromium early in my Linux days; I didn't really know the difference between Chrome and Chromium, so I just picked the one that was easier to install. Once I finally learned the difference, I consciously made the choice to use Chromium on all of my systems, even the non-Linux ones.