Metrication is the Path of Least Resistance
Metric is showing up in unexpected places. Major American sports broadcasters used to diligently convert international sport events from metric to imperial. More and more broadcasters are just reporting results directly in metric without any unit conversions. It's possible broadcasters are making deliberate decisions to go metric based on careful analysis.
It's much more likely that the switch to metric for international sports is simply because it's less effort. Going metric is the path of least resistance, and this is a good thing. Actually, it is THE reason why the U.S. will eventually go full metric.
It's Already Happening
If NASA made a deliberate decision today to give a press release using metric units the misguided imperial zealots would lose their collective minds. However, NASA scientists being interviewed on podcasts will often naturally use metric units and the imperial zealots don't come after them with pitchforks. Likewise, when a private space company, such as SpaceX, makes videos for the public in metric it's hard for there to be any significant backlash because SpaceX is a private company.
It won't be long before NASA can publish a press release in metric and nobody will have a psychological meltdown. We see a similar effect in online shopping.
Consumer Space
Consumer goods in the U.S. are mostly imported, and online retailers rarely do proper conversions to fractional inches for product information. Converting units takes effort.
Retailers are lazy so they convert product information to decimal inches or sometimes don't even bother. Who are the imperial zealots going to complain to? Americans see metric everyday.
Journalists are underpaid and constantly pressured to produce more content. They don't have the luxury of spare time to do proper unit conversions, so they are increasingly doing quick and dirty conversions to imperial decimal units, such as decimal feet. For example, a journalist can save time by converting 3.8 m to 11.8 feet instead of doing the extra math to convert to the more customary 11 foot 10 inches. These makeshift unit conversions highlight how kludgy imperial units are and will contribute to swaying public opinion away from imperial.
Cem by Cem
Everything that can be converted gradually will get fully converted to metric over time.
Some metrication cannot be done gradually. For example, aviation elevation in feet cannot be gradually converted to meters because mixing up units would literally cause airplanes to crash into the ground. Even countries that are fully metric, still use feet for elevation in aviation. However, the more common metric becomes, the easier it will be to metricate challenging domains like aviation.
Race to the Bottom
Australia and New Zealand did metrication correctly by switching all at once from the top down. Here in America we are going to do it the hard way from the bottom up, but it will happen.
Metric is more efficient and sensible than imperial, so it's ironic that metrication in America will be a side-effect of the world-wide race to the bottom.
There is no "if" in metrication — only "when".