feature phones are not a dominate thing in japan.

https://www.soumu.go.jp/johotsusintokei/whitepaper/ja/r04/ht...

86% of the population owns a smartphone. That's higher than the USA

Car navigation unit for Japan was great (still great for navigation functionality), so perhaps people don't need CarPlay than other countries where car navi unit is poor. Though now most companies sell their car with "display audio" unit with CarPlay support.

I dunno—Subaru figured it out.