The 3rd party Reddit apps made an effort to be more 'native', and actually used native UI elements to make rendering and interactions faster than the web page could.
WAAAAAY too often the 1st party native app is exactly what the other poster said: a browser context with access to some local native API's in order to hoover more data about the user. It is rare that a first-party app actually has some effort put into it to be a quality app. Is in fact so rare, that the sites that actually put in the effort suffer because folks can't believe that a native app for a site could actually be better or worth it.
WAAAAAY too often the 1st party native app is exactly what the other poster said: a browser context with access to some local native API's in order to hoover more data about the user. It is rare that a first-party app actually has some effort put into it to be a quality app. Is in fact so rare, that the sites that actually put in the effort suffer because folks can't believe that a native app for a site could actually be better or worth it.