Because "best dentist near me" is a fundamentally local question, and the engines treat it that way. Search-enabled AI can factor in where the asker is, and engines grounded in map data lean heavily on local business listings. Two people in two cities asking the identical question get different answers by design.
That's why our local probes test with location context, and why your Google Business Profile and Maps presence matter so much for local businesses — for several engines, that's the source of truth they're reading from. If it's thin or inconsistent, you're invisible for exactly the "near me" questions that convert best.