Will Apple never fix the memory problems with Netflix and Facebook?

I see not only me, but many people are having the same issue when watching Netflix:

"This webpage is using significant energy. Closing it may improve the responsiveness of your Mac."

How in the heaven? I have 16GB DDR4 RAM in a quad core i7 and while I am using Netflix nothing else is open.

As for Facebook, it simply crashes from time to time, it prevents me to open the emojis list, it froze when loading older posts... I even installed Chrome, because I thought it could be Safari, but no! The issue happens in both browsers.

I don't like this kind of limitation. We buy Mac thinking it is great and powerful and such simple tasks becomes a burden? I really regret buying it... I wish it would still have time to return it.

If anyone has any tips, I am glad to receive, because I followed many tips on existent posts but nothing helped. It becomes clear that this is an OS issue and that Apple SHOULD PAY ATTENTION.