My problem with this approach is the same one raised by Dijkstra against the goto statement. These update actions are too unrestricted and don't offer any way to analyze the program's progress systematically, based on the program source code.
The same can be said of a React frontend that talks to a JSON API. There is some structure, organization, and convention to the API endpoints, one-way data flow, and so on. Otherwise it’s chaos.
On our most recent project we do the same with Django and HTMX. Organized endpoints by component. Composable, reusable server-side components with django-components [1]. And we’ve been orders of magnitude more productive, shipping more in 1-2 months than we did the previous 12-18 months working with React.