Webpage using significant energy / memory on Mac

I just recently switched to Safari after using Chrome for the last 9 years. I made the switch for 2 main reasons; 1. Privacy. 2. Performance of my MacBook Pro. I had read that Mac's get better performance and battery life by using native apps. Getting this message kind of makes it seem like the opposite is true. Really confused by this and surprised Apple has not at the least addressed the issue or explained why it does this?

Thanks! I had the same problem as the op and your solution worked for me.

I did that as I'm experiencing the same issue and it did not resolve the problem.

I have this question, too.

I have it too. I don't like it. Tried everything above. Only since the update. APPLE- this is not a feedback suggestion. Please fix the issue. For the price of a Mac is the best they can do?

I installed update on 4/24 and it did not fix the issue. I have a brand new 27" iMac.

This is a new Security update that just came out today. It is seperate from the update to version 10.13.4.

It might of rolled out to you today, however I installed it on the April 25

and it changed nothing in relation to this issue.

"I opened "Develop", "Experimental Features" and unticked "Cache API""

Not being a tech, I have no idea what that means or how to do it.