No they are (were) an actual native Android apps that install automatically without needing to go through Google play. They have a much tighter sandbox and restricted access to system APIs as a safety measure.
From a user experience level, yes it’s pretty similar, with the important difference that after fully loading the instant apps were supposed to work as native installed apps.
“Instant apps” = PWAs?
No they are (were) an actual native Android apps that install automatically without needing to go through Google play. They have a much tighter sandbox and restricted access to system APIs as a safety measure.
No, it was a feature that allowed “streaming” a real android app without needing to install it
So a Java Applet?
From a user experience level, yes it’s pretty similar, with the important difference that after fully loading the instant apps were supposed to work as native installed apps.
Well I’ve never even heard of it so I guess I shouldn’t be surprised that it was unsuccessful.