Welcome, BEsupport, to Apple Support Communities!
We see that you are seeing Safari’s CPU usage markedly increase, at least sometimes, when on LinkedIn pages.
LinkedIn uses a number of dynamic webpage features, and, those of us that have looked at some of their code are not impressed by their techniques.
I usually use Safari when I access LinkedIn, and I have seen Safari “complain” about the pages taking up CPU time (and memory). (Safari version 13.1.2 on macOS High Sierra version 10.13.6, on a Mid 2010 MacBook 13-inch, 8 GB RAM.)
I usually ignore the “complaints” with very few issues.
Unfortunately, I’m not sure there’s much you can do, on your end, or even much that Apple can do.
LinkedIn keeps promoting their own Apps, though I have seldom found any benefit to using their Apps (however, I haven’t checked CPU usage while using their Apps).
You could try other browsers, to see if any fair better, on LinkedIn.
(I haven’t used my newer Mac, running Catalina, to see how well Safari does on LinkedIn, there. I use that machine for my more compute intensive tasks.)
Especially if you see the same sorts of troubles on other major web browsers, you could take your issue to LinkedIn.
