My kids are spending hours of class time in school learning Roman numerals. The correct amount of education about Roman numerals is a short form video of math trivia when you're 23. Zero classroom time should be wasted on an inferior system of numerals.
Learning to read Roman numerals is secretly an exercise in mental arithmetic. You're summing numbers in your head as you go, and occasionally you'll need to keep that sum off to the side while you subtract a second number from a third. So rather than viewing it as time wasted on learning an obsolete numeral system, instead consider it as a different way to frame a math exercise.