MY site hosted on Digitalocean, without ads it's loads in just seconds as google speed test.
- FCP 2.4
- FID 190 ms
Rating 73 But with ads, it's too much slow rating only 48
I am using a wp-rocket cache plugin, maybe there is a reason. my site: https://techpanga.com/
You can't cache the Ads (so wp-rocket won't help there) but they still count towards your page speed score.
Ads on one page I tested added over 1MB of data so it is hardly surprising that they slow the page down.
As you have no control over the content presented by the Ad networks your only option is to delay the Ads loading by initialising the Ads after several seconds.
This, however may reduce the end user experience even further as once they start reading a page the Ads may load in later moving the content around.
Other than providing Adverts directly yourself (which is difficult) there isn't much you can do I am afraid.
Perhaps you could move your Ads to the sidebar and lazy-load them in so you still get your revenue without ruining the experience of your users?
A simple
setTimeoutwrapped around your Ads initialisation normally works but it depends on your Ad provider.