I see only one reason to use custom JS UI stuff in a project: if it's an internal tool and you and your colleagues (and all your tech department) use those comp

I see only one reason to use custom JS UI stuff in a project: if it's an internal tool and you and your colleagues (and all your tech department) use those components when programming. Otherwise i would use a framework, it's much reliable. If you don't want to deal with the React/Angular complexity, try Svelte, it has the best dev experience if you come from vanilla JS development.