I'll add one factor which the other already good answers didn't mention in detail: weight.

Modern cars have several dozen of fuses, each weighing a couple of grams each. Imagine replacing them with even the smallest automatic breaker you find, for example this:

and look at the specs:

It weighs ten times more, not mentioning it's much bigger and the endurance to the environmental conditions is nowhere suitable for a car. And probably improving its environmental endurance will add still more weight.

Bottom line: you'll add kilograms of weight for no more than a very small convenience (resetting a breaker instead to change a blown fuse, event which in normal car operation is quite rare). In exchange you will have a heavier and more expensive car.

I'll add one factor which the other already good answers didn't mention in detail: weight.

Modern cars have several dozens of fuses, each one weighing a couple of grams. Imagine replacing them with even the smallest automatic breaker you find, for example this:

and look at the specs:

It weighs ten times more! Not mentioning it's much bigger and the endurance against the environmental conditions is nowhere suitable for a car. And improving its tolerance against an adverse environment will probably add still more weight.

Bottom line: you'll end up adding kilograms of weight for no more than a very small convenience (resetting a breaker instead to change a blown fuse, event which in normal car operation is quite rare). In exchange you will have a heavier and more expensive car.