Nice overview! A few comments:

- homomorphic encryption is much much faster now, so the latency argument against won’t hold much longer

- with multi-key FHE, you could replace MPC, without the integration complexity and increased bandwidth cost

- Trusted Execution Environments are not about protecting user data (that’s the purpose of FHE) but rather about protecting the software itself from people having access to the physical machine. An example would be running a sensitive ML model in the cloud: you would want to use FHE to process the user data encrypted, inside an TEE that would protect your model from the cloud vendor.