Even if you’re not A/B testing you’re going to have some validations that only happen server-side because they require access to resources the client doesn’t have, but I don’t see either of these points as arguments against sharing the validators that can be.
I agree. These points are arguments against the philosophy of HTMX which asserts that you can get everything you need without client-side logic.
To be fair, I'm also not a fan of bloated libraries like React and Angular. I think we had it right 15-20 years ago: use the server for everything you can, and use the smallest amount of JS necessary to service your client-side needs.
