On one hand yeah, the majority of users just uses whatever official tools are available.
On the other, reddit doesn't really have any exclusive or paywalled content like Netflix does - if alternatives like Lemmy manage to acquire a critical mass of users, we might see a shift, but IMO i don't really see it happening anytime soon. The average "normie" user of reddit will probably just shift to another big name like twitter or facebook (which still has 6x the monthly active users of twitter, as much as people on the internet pretend it's dead)