Safari using significant energy

I am currently using a 2017 Mac Pro touch bar that is still on Mojave 10.14.6. My safari is consistently shown using significant energy on my menu. In my activity monitor, I noticed there are many apps running behind my safari despite only opening 4 tabs: mailbox, youtube, google and apple stack exchange. Is there any way to remove the apps shown running as shown in the screenshot and to prevent safari from using significant energy? (The attached screenshot is the activity monitor for my safari)