I see! So in essence there is no current flowing into that uA range at all? If that can be done, why doesn't those 10A multimeter function that way too? I'm not EE trained apologies for the question
No, the current measured by an ammeter always flows through the ammeter, regardless of the scale. Kirchoff's current law, combined with the way you hook up an ammeter, guarantees it to be so.
The Fluke 116 can measure up to 600 uA.
Many typical meters can measure up to 10A, or 16,666 times more current.
The shunt resistance isn't strictly specified in either case, so that ratio of max scale readings isn't a very precise indicator of what kind of protection is required, or what kind of current spikes might happen if you stuck the probes directly into a wall socket. But as a rough order of magnitude, the Fluke 116 is dealing with less than one ten-thousandth of the current that a typical 10A meter handles. That's why the protection strategy can be different.
But why can those meters measure like how the 116 measures current? Isn't that safer? And no concerns for burden voltage
They DO measure current the same basic way. It's just that the currents are orders of magnitude higher on most meters, leading to orders of magnitude greater levels of power being dissipated in the meter. And burden voltage is always a concern (the 116's microamps range is nearly useless for general electronic purposes because of its high burden voltage).