I lived out of the country for a long time and had to use Metric. Now that I’m home I use what is easiest for the job. Think of it as “Spanglish” where the word that best fits the situation pops out. :)
Anything requiring “mass” in the calc is best done Metically.
I’m living in Germany now. Metric is best for science/technical uses. But the units are out of whack for daily use. The kilometer is a short unit of distance so useful highway speeds are in the triple digits. For height, you have to use fractions of meters. Useful temperatures also require fractions, as Celsius degrees are too big.
Traditional units were based upon daily use, and are much easier to handle for normal life. Which is why the metric system was mostly imposed around the world by government fiat. When you go to the U.K., nominally a metric country, speeds and distance are still in miles/mph and weight is in stones/pounds ( 1 st.= 14 lbs).