Website Plug-in safe

As we know, millions of plug-ins are available.

We have a website that is used by thousands of customers.

Unfortunately, we noticed that more and more plug-ins are interfering with our code, causing unexpected behavior and causing a bad user experience for our customers.

Some of them are explicitly installed by the customers themselves (as sticky password), others are installed as Spywares.

Is there a good practice to avoid Plug-ins interference? Could not use Javascript at all, but that's not realistic in a web 2.0 world... ☹️

Thank you for your answers.