Metric allows you to convert between length volume and mass in your head. Someone smarter than me could probably take a reasonable estimate of how long a kettle will take to boil just by knowing it’s wattage and estimating its volume.

You’re right that “pounds” may have e been a practical measurement back when people didn’t have calibrated and everyone’s hand weighed a pound. However, that advantage ceased once everyone standardised those measurements.

A metre is equally divisible by 50, 25, 20, 10, 5, and 2. There arr numerous advantages to a base 10 system.