Why have you added a amazon search feature onto my browser?

Why have you added a amazon search feature onto my browser? Firefox removed the FIND feature (CTRL+F) so it does not work on every tab. And the extension to revert to older FIND feature does not work. I used that search feature continually, but it doesn't work any more... What an aggravation. And instead ... Firefox put Amazon search onto the browser/ see attached image. The other day my 'preferred search engine' was hijacked by Amazon, so that every search result came up an Amazon page.... no other results possible... just Amazon. I chatted with Amazon and told them I would no longer buy from them. Obviously Amazon paid Firefox to alter my 'search engine' and 'add another feature' to my browser... at the same time they downgrade the Find feature ... I guess we're supposed to forgo 'research using Find feature' so we can mindlessly 'search amazon' Corporate.