For real its not The thing is S6 support vulkan that works with new androids and thats the requirement for new android also i find out S6 works better than S7 in android 7 but if
samsung dosent change the UI you can have android 8
apps of S8 in your phone just normally by updating them from APKmirror
site I have all note 8
apps on my phone with no root and in stock rom No bugs and no force close Also installed messages contacts dialer edge screen and many more