Magento2: Override issue for lib/web/jquery.js

Question

I am trying to override below file in my custom theme.

lib/web/jquery.js

Seems it been override. But It stop other jquery from working.

Due to this a lot of console error arise.

Here is my code

app/design/frontend/custom/theme/requirejs-config.js

var config = {
    map: {
        '*': {
            'jquery':'js/custom-jquery'
        }
    }
};

I have placed my override file here:

app/design/frontend/custom/theme/web/js/custom-jquery.js

Can anyone please suggest how to override lib/web/jquery.js properly.