alt Hacker NewsThe law that requires allowing alternative browsers, the DMA, applies to the entire EU.
But I believe there are still zero third party browsers, to publish their browser in the EU Mozilla need an EU development team because developers outside the EU are unable to install it, and Mozilla cannot publish it as their existing app. Enforcement is taking years.
I'm pretty sure the OP knows about the law being EU-wide, but they were referring to "the EU and Japan ... those two countries".