1. Have a project with some textures, fonts, audio clips etc.
2. Switch editor to Android platform (assets reimport, fine, expected).
3. Go to Project Settings -> Other Settings -> Graphics APIs, change them (e.g. remove Vulkan).
4. Assets reimport immediately!

This is not expected. Things like textures (especially uncompressed textures) should not depend on the graphics APIs. Much less Fonts etc.

Another similar sounding case: https://issuetracker.unity3d.com/issues/changing-playersettings-dot-graphicsapi-reimports-all-textures-regardless-of-their-compression-settings (case 1182352) has been marked as fixed but the behavior above does happen, at least in 2021.2.

Internally it seems that the cause is that assets record a "ImportParameter/Platform" dependency, with values like "platform:13;extendedPlatform:0;subTarget:53687091" or ""platform:13;extendedPlatform:0;subTarget:524288", i.e. the subtarget part includes the graphics APIs.

Regression started to happen with asset database V2 (ADBv2); v1 did not have this issue