- Apple's keyboard has richer context; third-party keyboards are largely limited to the text proxy (surrounding text/selection) and cannot inspect the host app/see the underlying context of where the text is used/what for.

- No caret/cursor control; cannot reliably set the cursor to arbitrary positions

- No custom dictation pipeline inside the keyboard; must rely on system dictation (or move voice input outside the keyboard).

- No camera access from the keyboard extension; blocks scan-to-type (OCR), QR/barcode capture, etc.

- Can do basic text expansions, but cannot implement privileged automation/macros that interact with other apps/UI or run broadly in the background.

- Due to aggressive lifecycle + tight resource limits constrain large language models/dictionaries; cloud sync/personalization