Having a standalone Siri app has more benefits than just having a log of all the questions one's asked the assistant.
Of course, it's great to have all the chats so that one can revisit/reuse them later, but there's one very important additional benefit.
Much like Claude projects, the different Siri chat bubbles can be trained to perform some specific tasks, and Siri understands the context and keeps it in memory.
For instance, I've set a calendar bubble, a video scripts bubble, reminders bubble, and more.
Siri behaves differently in each chat. For the scripts portion, I've given it around 5 of my past scripts and it's now understood my speaking patterns, commonly used phrases, and more. If I ask for a script elsewhere, it gives a rather generic script.
Cool stuff.