The great white is right at the top of the food chain. We can get by without them ..... There will just be ... more seals.
You need to learn some basic ecology.
When you remove a top-level predator, you get massive side-effects over the entire system. For example, when we stopped the action of the two top level land-based predators here in southern Australia (Dingos and humans), large herbivores increased greatly in number, causing much damage to the plant community through opver-grazing with consequent effects on plant-dependent birds, mammals, and insects. Mid-level predators increased out of control too, in particular foxes and cats, and that has led directly to many species extinctions. (Yes, Dingos are introduced too, but the vital top-level predator role they occupy was previously filled by other creatures, now all extinct. From the point of view of the overall system, it doesn't much matter which species plays a role, just sop long as that role is filled.)
Another example: when wolves were exterminated in the Rocky Mountains, Elk were able to graze in areas that had never been safe for them before, and that led to vegetation loss which in turn led to erosion problems and poor water quality, not to mention serious habitat loss for many other creatures.
And sharks. When you eliminate big sharks, you do indeed get more seals (and other things) and these eat more fish, and that means all sorts of other effects - notably, a reduction in fish catches which means job losses and food price rises. Any time you mess up a working system, it hurts, and this silly call is just another example of that. (Note also that it is possible that the increase in the number of attacks has to do with difficulty in finding enough fish further out to sea where over-fishing by humans is getting worse every year. I have no evidence for this, I just mention it as a reasonabnle possibility that could be investigated.)
What you
can do, however, is think about purely local measures to make the beaches safer. Whether that might be in the form of careful selective culling, some method of driving the bigger sharks out to sea further, or some other action, I do not know.