Personally I don't mind it, but would say the main advantages offered by JSX for this kind of work (see: React Three Fiber) are more in its ease of composition and structuring larger projects.

Often in R3F projects you'll end up running per frame animations via the normal declarative property API in the useFrame hook anyway, as adjusting props in a loop is not great for performance. The JSX instead becomes a way to easily understand the hierarchy and nesting of objects, as well as quickly mount/unmount new elements.