In the EU, Google was forced to allow non-Google default searches in their operating system. They have a list of requirements that I think is fully met by the Kagi app: https://www.android.com/choicescreen/dma/searchengine/
- General search provider: Yes
- One app per company: Yes
- Localization: Yes
- App in Google Play: Yes
- Branding Requirements: Yes
- Web Search Experience: I would hope so
- Functionality required: Yes
- Android OS support: Yes
- Minimum installs: Yes
- No connection to non-EEA state actors: I would hope so
There used to be a requirement that the app is sufficiently popular, but that seems to be removed since I cannot find it on the page.
There is a relevant part in the page which is why it would be worthwile to tackle that in this year:
Application windows open twice a year at the beginning of the year and during the summer.
This would also be a possibility for Orion once a Android app comes out and has the 5k downloads.
A lot of other searches have been added to the list: https://www.android.com/choicescreen/dma/searchengine/options/
It'd be nice to have the app integrated into the OS as well as Google is. At least for EU citizens, this would be possible natively. I have also found some ways online to trigger the choice screen for US residents, this might be a nice thing to add to the documentation (although it requires using adb which is non-trivial for average users).