Every time you add a plugin you’re adding more files for your website to load.
This is is okay for pages where they need the functionality of that plugin, but often these files load on pages where you aren’t even using the plugin, so they’re adding load time when they’re not even needed!
Caldera forms is a good example of this, which you might only use on the contact page, but it loads on every single page.
There are methods to get around this though.
You can use an asset optimisation plugin which lets you decide which files load on which page.
A popular free plugin is called WP Asset Clean Up.
We prefer to use Perfmatters, as they have more features and the interface is easier to navigate.
Both plugins have good documentation to help you set them up.
Be careful when doing this though, as you might think a file isn’t being used and turn it off, but in fact it’s a critical file and will stop break the page!