I was a web developer before jQuery, during jQuery and still am after jQuery. You really want react/similar even for very small apps. I went and tried to implement a simple calculator app without any dependencies just to see if it got better with Web components, but not really, way too limited to be useful for anything other than purely design tokens if you don't want to reimplement React. jQuery is not really necessary any more, the problems it used to fix are solved - but there is still no support to make a reasonably organized and performant reactive application.

BTW not sure what you mean with the useMemo - I built very large applications in React (hundreds of complex dynamic financial analysis pages) and didn't have much problems with it - could you go into detail please?