We can discuss all sorts of reasons why one system is better than the other one but the worst situation is to have more than one system to measure the same thing. Measuring longer distances by foot instead of meters makes the error bigger. Many small feet adds small amounts of errors on each foot. One meter is an average step so less errors that adds up.

Choose one and stick to it :-) Customary xkcd: https://xkcd.com/927/