Rendering template partials server-side and fetching/loading content updates with HTMX in the browser seems like the best of all worlds at this point.
Until you need to write JavaScript?
Then write it. Javascript itself isn't the problem, naive third-party dependencies are.
Developers are perfectly fine with writing insecure JS all by themselves.
Which should be much less than what’s customary?
But that's the neat part, you don't!
Until you have to.
The only way to win is not to play.
Let me quit my job real quick. The endgame is probably becoming a monk, no kidding.