There are lots of tools that it's not reasonable to expect a random home kitchen to have -- expensive grinders and mixers, mortar and pestle, double boilers, marble rolling pin to press out pastry, etc. But a kitchen scale is just a huge win for any kitchen. They don't take much space, they're not at all expensive, and it takes less time to convert "half a cup of flour" into grams using your phone than it does to wash the measuring cup.