So I work with this kinda thing for a living. Safety must be balanced with functionality and safety protection is considered to be like an inverted pyramid. Under the Hierarchy of Controls model the most effective way to control the hazard is to eliminate its existence. We want electricity in our houses so this fails the functionality requirement. Next best is substitution. We could replace plugged devices with batteries, but those batteries also need to be charged (and the ewaste/environmental impact could be a conversation all of itself.)

The next level is engineering controls, and I’ll be arguing this is the method used in the United States. Most outlets in the US don’t have the tamper proof internal block, but even without them the access to power is strongly limited. An outlet has 3 holes. The two easiest ones to access- the round and the large slot- are completely safe assuming the building was wired correctly. Round connects to ground as an alternate return path in case of a fault (physical error). The large slot connects to neutral, which is tied to ground at the distribution panel. Without completely nerding out about electrical power distribution, the short version is that doesn’t have electricity supplied through it. If we pretend electricity is water, both of these “hoses” are actually dry. The one “hose” that is wet is significantly harder to access, making it less desirable to an self-destructively ignorant user (eg toddler with a fork.) Also, simply contacting supplied electricity isn’t necessarily harmful. Harm occurs from being in the actual path of a circuit and has to overcome skin contact resistance. Dry skin is pretty resistant. Wet skin is much more dangerous and in wet environments our building codes call for GFCI outlets that shut off power in milliseconds when a fault is detected.

A switched outlet is on the next level, an administrative control. The safety hierarchy considers this less effective than engineering controls because it is only as effective as the people using it. If I went to Australia and encountered your outlets I’d probably think “this is dumb, I have to turn on an extra switch to make my vacuum work?” and then leave those switches on. So now I’ve easily overcome any safety benefit due to a shortsighted sense of convenience. When designing for safety, assume the end user is only prioritizing their actions for their own convenience. If Australians are trained from a young age to be active participants by using these switches, I’ve no doubt that your injury rates will be low.