I have a Amazon tablet, too, that I use to access my Evernote notebook for recipes in the kitchen. I did sideload the google play store, and it sort of works, but it’s not completely happy. And it just refuses to load the Evernote widget. And forget about trying to load Netflix on it. It just won’t. I don’t know why they have to make things so difficult.
Kodi was one of the apps that kept disappearing on my Fire stick. I imagine if I had kept up with the Amazon Firestick forums, and kept track of which update server IPs I was supposed to keep blocked, it would have been ok, but who’s got time for all that? Amazon wants you to see their stupid menus and advertisements, and they try their best to make you do what they want you to do.