Why would Amazon want to do that? Browsers are pretty much given away for free. So you have to consider, when deciding to write one, what the benefit will be to you. So far, the benefits have been:
IE: User lockin to Microsoft OS.
Netscape: Commercial, browser and later connected products but not browser sold to people.
Firefox: Nonprofit, going for open source. Some proceeds from linked services (Google as default search engine, etc.) to support development.
Chrome: Data! Your data! On our systems!
Chromium: If we make this open source, people will fix the problems we made and we don't have to pay them. And later, people will use this and we can gain market share.
Safari: We're Apple. We build everything that runs on our systems. Our systems want a browser, so we're going to make one. (Side note: Safari uses webkit, which is also not chromium.)
Edge: Data! Your data! On our systems!
Edge-chromium: Data! Your data! On our systems!
If Amazon were to write a browser and remove all the tracking, what would they get? They wouldn't get data. They wouldn't be able to lock people in to another system. The only thing I can see is being able to advertise a bunch of Amazon products, but if they're not tracking your activity, they're likely to advertise a bunch of junk that nobody wants anyway. If they did decide to make a browser, I am certain it would track too; it doesn't benefit them sufficiently otherwise.