Don't worry, they will notice a difference when the content eventually stops or drops in quality, or at the very least a large portion of it will move here
As for the app thing, they're clearly ignorant and don't know what they're missing. That or they grew up with gross filtered feeds that were literally engineered to be toxic and addicting. Even I remember how addicting that shit was before they went a bit too crazy with ads and irrelevant posts. Used to be you could scroll and scroll thru Facebook and you wouldn't run out of interesting posts from friends, groups etc. Now it's all pages I don't even like or follow. Adpocalypse 2.0
I've been using RIF and old.reddit.com for as long as they existed. Reddit since the big Digg transition. Hope to never see the same happen to Lemmy!!