Getting by without Japanese in 2026 — where does English work, and where will it stop you cold?

Major tourist hubs (Tokyo, Kyoto, Osaka) now have plenty of English signage, AI-translated menus, and staff who can manage basic English. But the gap between "Tokyo Station" and "a yakitori counter in a Toyama suburb" is huge. What's the realistic English-comfort line in 2026 — train systems, hotels, ATMs, casual restaurants, ryokans, taxis? And which phrases or apps close the gap fastest when English does run out?