It looks like the new Google's Pixel 4 watch comes with yet another incompatible change in charging technology. This is a ridiculous situation. The original Pixel Watch used one type of wireless charging. Then the Pixel Watch 2 & 3 removed wireless charging and swapped to a different charging mechanism. And now the 4 has changed again. So three different charging cables in under three years.…
If you mean a USB-C port in general, they can be made waterproof. If you mean something specific to putting one in the most compact form factor possible, that might be true.
And that requires more space than a typical port. In a compact device that is difficult. A flashlight is literally one of the simplest electronic devices there is and bulk is often a plus for comfort.
You might be surprised at everything going on inside a modern flashlight. I’ll grant that it’s probably easier to find room for extra seals around the port than in a smartwatch though.
Still not nearly as complex or compact as a smart watch. A little microcontroller versus an arm processor.
A switch mode LED driver can be made very tiny with as few as 4 components. Battery protection and a single cell battery charger can also be very simple.
Then again my flashlight has a microcontroller with open source firmware on it
They can be waterproof but are also non functional until the water is fully cleared from the port.
That kind of waterproofing wears over time (years). It keeps it’s resistance, but not a submersible seal. Watches have longer use years than phones on average.