The difference in programming model IS THE advantage of HTMX. Changing from react to preact is a perf optimization.
If you are doing the SPA thing correctly you must duplicate business logic (data validation). Also when your API just sends "dumb data" (JSON) to the client, you are forced to make changes to the backend and frontend in lockstep.
If you are doing the SPA thing correctly you must duplicate business logic (data validation). Also when your API just sends "dumb data" (JSON) to the client, you are forced to make changes to the backend and frontend in lockstep.