>Why would you expect that third party specifically trained their model to be more aligned to you and your needs than to them and their (business) needs?

That is my point. Why do you think Gemma, a local model trained by Google, is aligned to you and not the values of Google.

You can similarly have a model aligned to you which you pay someone to remotely host for you instead of running it locally.

Think of AWS. If you break their ToS and host a pirate website there it will work despite being misaligned from AWS. You are that sole master of the software. AWS is the sole master of the "hardware." Now ultimately hardware has control over the software so technically AWS could just hack into whatever code you are running and do what they want, but in practice they act solely as the master of the hardware and will tell the hardware to "shut down" if they catch you acting out of their alignment.

With local models just because you are providing the compute, that doesn't mean you are the master of the model and it is aligned to your interests. You could just be subsidizing inference for a model aligned to someone else.