I feel like off-chain ZK applications are really undervaluing the potential of just using STARKs, including for privacy-demanding use cases.

These days a STARK is < 100 kB, for off-chain use cases that amount of  bandwidth is utterly trivial compared to the client-side prover time savings that come from using STARKs.

Totally spot on! STARKs are a no-brainer for off-chain apps. Proofs under 100 kB? That's peanuts for bandwidth, and the client-side prover time savings are insane. Plus, with no need for a trusted setup, they're perfect for privacy-heavy use cases