They use a blend of metric and imperial as do we.
Aljernon
We should bring back hogsheads, rods, fathoms, etc.
The tipping point was when smart phones with inexpensive internet access became common. Before that, the least intellectually curious among us rarely had computers or internet.
Reddit is and has been going downhill fast. There were benefits to it being embraced by the masses but also huge downsides. The admins made decisions that negatively affected the experience of using Reddit (like refusing to let subs disable voting even when it made alot of sense) because they wanted to maximize engagement by any means necessary. But taking reddit public was the final nail in the coffin. Now they hand out temporary and permanent bans not because their rules were actually violated but to protect their stock price and corporate reputation.
Metric is useful but it lacks enough units for everyday use. Like milimeter is useful for measuring somethings, and meter is useful for somethings but not having a foot equivalent makes it less useful. I'd rather say 4 feet than 1.3 meters. Same with grams and kilos; not having an ounce is an oversight. I'd rather order an 8 ounce burger than a 226gram burger. Mililiters and liters are useful but not having a fl ounce makes it clumsier.