JavaScript should not be used to handle business logic

This question, I now understand how to describe this has puzzled me for a long time, in the company's projects, JS for data validation played a big role, but this makes the whole project business logic fragmented, even chaotic

Now this is the case with the company's projects. Now think about why the service layer in the company project is so simple, why the action often does what the service layer does.

If you use pure Java to do business logic, to do data validation, it is also possible, spring framework, but now I can not master, I also need more practice

My idea now is that JavaScript, or even very useful jquery, should be used to handle the page display, and that the business logic is all controlled by the backend, so that the business logic code is clear, and perhaps the idea is wrong, perhaps right.

JavaScript should not be used to handle business logic