Yeah, every system has pros & cons. I think the lack of an approximately-one-foot (30 cm) unit in metric is clumsy to work around, and I think degrees-C are too wide. We can argue about the details if you find it fun ("yards in a mile" does not come up all the time), but they're all evolved from hundreds of years of usage, and that means they all work fine at the end of the day.

> I think the lack of an approximately-one-foot (30 cm) unit in metric is clumsy to work around

What's clumsy about 30cm though? If you are working at scales where this level of precision is needed, you can just use cm throughout, and the beauty of metric is that even someone who has never had to do that before will know immediately how much it is because conversion to meters (or millimeters, or whatever the primary unit is in their usual applications) is so easy.

Similarly, I've heard similar sentiments expressed about lack of pound equivalent in metric. But in practice we just say "500 grams" etc (and for bonus points you get 400 grams, 300 grams etc).

Miles and yards are both used as units of distance, so conversion is obviously relevant. The only reason why "yards in a mile" doesn't come up all the time is because Americans work around it by subconsciously (?) avoiding any such cases where the conversion is non-trivial. E.g. a road sign in Europe might say "400 m", whereas in US a similar one will be "1/4 miles".

And "evolved from hundreds years of usage" generally means a lack of internal consistency, because most units originated a long time ago as a way to measure something very specific - in many cases, something completely irrelevant to most people using those units today. Nor did those units remain consistent through history - just look at how many definitions ounce has in US in different contexts, all of them historical! Or regular vs nautical vs survey mile. Even just cleaning up that mess would be a massive improvement.