I too find this frustrating, but I’m curious about the claim that Chrome is the most common browser on Mac. I sometimes see this claim, but I struggle to find any data to back it up.

The US government web analytics (https://analytics.usa.gov/data/), which seems like a reasonable source for general usage in the US, show Safari substantially ahead of Chrome on Mac.

Have you seen any sources that show Chrome ahead of Safari on Mac for a general audience?

I believe this is as much on the Chrome side as it is on the Apple side: https://bugs.chromium.org/p/chromium/issues/detail?id=312105

Chrome could access those natively on Mac, or use the keychain as the native backing store, from what I can tell.

You can, Apple has an extension for iCloud Keychain.

https://chrome.google.com/webstore/detail/icloud-passwords/p...