Well fridge should not go below 0 Celsius or you have trouble

There are things in the world other than fridges.

When thinking about boiling water

I only really do this about 1% of the time I need to use temperature.

Even IF Celsius and Fahrenheit were equally good for most purposes, it would be easier if every continent used the same system. Why, because people travel, often from continent to continent.

This is really the only reason to use Celsius: it works well with other things.