Update: As noted by Nick Heer on his Pixel Envy blog, analytics data is unreliable because Safari on iOS 26 is reporting a different operating system version in the user agent string that analytics services rely on for data. For example, devices on several versions of iOS 26 are reporting themselves as being on iOS 18.7 when using Safari. The relatively low number of mobile devices correctly reporting themselves as being on iOS 26 are largely from users on alternative browsers such as Chrome.
My phone may already be doomed to iOS 26, but I’ll hold onto macOS 15 as long as I possibly can.