I've used both and I prefer the htmx approach. React/NextJS are what over-complicate things - particularly when it comes to server vs client side rendering and hydration, state management, passing props, caching, static site generation, slow and fragile development environment etc etc etc.
I recently rewrote a site that was built in NextJS into Go+Echo+Templ+HTMX+AlpineJS, keeping just the Google Maps and Facebook components (but only injected as necessary, rather than needing a whole App wrapped around them)
The result was about 50% of the size of code that is much easier to reason about and test, better performance, simpler and smaller (size and resource) deployment - essentially better in every way.
I recently rewrote a site that was built in NextJS into Go+Echo+Templ+HTMX+AlpineJS, keeping just the Google Maps and Facebook components (but only injected as necessary, rather than needing a whole App wrapped around them)
The result was about 50% of the size of code that is much easier to reason about and test, better performance, simpler and smaller (size and resource) deployment - essentially better in every way.