Yes. Browsers have security flaws and they run code downloaded from unknown places just by visiting a web address, and that can compromise them. That code can be contained in images, in font files, in videos, in JavaScript, etc. That is a large reason they are updated so frequently. If you want to prevent that possibility you would need to have a layer of protection around your browser. That is what whonix is for.
So then what's the point of the "safest" setting within Tor Browser (i.e. the setting that disables scripts such as Javascript)? When I say "safest setting", I'm referring to Tor Browser's "security level" feature.
I understand that Whonix adds another layer of protection, I just want to know if Tor Browser alone (with the highest security setting) is dependable.