@Gargron @petergleick to clarify in case anyone misses the exact meaning: app development costs money and the official app is more than just an embedded web browser, so it takes dev time (and therefore money) to add those features there as well.
Personally, when I was using Mastodon I wouldn't have minded the official app being a modified embedded browser. Notifications were the only reason I had the app installed really as the mobile web page is extremely similar and has more functionality (because they don't have to re-create functions).