I had an S and traded it in for a Model 3. I ended up liking the Model 3 more since it's much more nimble and gets the latest software updates. The S was nice, but felt like I'm driving a boat.
S is a different body size entirely, and Model 3 has some more advanced tech (e.g. more power-efficient) until S refreshed. 3 is actually cannibalizing S sales.
Perhaps I'm missing something, but how does anyone know that it's "cannibalizing" S sales rather than just "S sales are down?"