Hello,
Are you doing it? Have you noticed any impact on google play ranking / downloads?
It is a requirement if you want your app featured…
i have some apps with and some without those marketing images.
however i couldn’t see any differences in downloads with or without them.
I know, but it’s not only requirement. And i doubt my apps would be features.
If you believe your new app got chance to get featured - invest some time to prepare those assets, if you are planning to make some quick app (or quantity over quality) don`t bother, but up to you.