The real question is how much healthy tooth remains
A filling is often a good choice when the tooth can still be repaired conservatively. A crown is more likely to be recommended when too much structure has been lost for a filling to hold up well over time.
The decision is usually about strength and long-term predictability, not about automatically choosing the larger treatment.
When a crown may make more sense
A crown may be the better option if the tooth is cracked, has a very large old filling, keeps breaking, or has already had root canal treatment. In those cases, covering the tooth can help protect what remains.
If the tooth is still mostly intact, a filling may be enough. That is why a clear explanation matters more than the treatment name alone.
What patients should ask
Ask what the tooth is at risk of if you choose the smaller repair, whether the bigger restoration is about strength or appearance, and what the long-term outlook looks like for each option. Good restorative planning should feel transparent, not vague.