From Tech Reflect:

I don’t know if this is a macOS or iOS specific thing, but it’s a trend on those platforms in recent years that is very frustrating. It’s hard enough finding things on the internet but once you find them, it should be easy to find them again.

The order in which iOS shows you Siri search results is indeed puzzling. I get there’s a privacy v. convenience tradeoff argument that can be made but it’s not that this data isn’t on your device in these instances. I feel the pain of this whenever I dabble with Apple Maps in particular. Addresses of people I’ve taken the time to create contact cards for or based on areas it knows I’ve been to should be prioritized and used in search results, yet it rarely is (Apple has a TON of information in my travels on my local device and seems to completely squander it).