Why does Safari never work?

When I need to do something in for example Facebook, the page doesn't respond. Like there's no connection. I press reload and nothing really happens. I then simply open Firefox and do what I needed to do. When i switch back to Safari it's still "loading", but not really.

I would just be elated if I could have a browser that just works. Chrome and Firefox uses too much battery.

Also .webms never play which is super annoying. Get it together, Apple.