Update reasoning.

Author: lgarron

README.md

@@ -38,7 +38,8 @@ if (jsonWebAuthnSupport) {
 
 `@github/webauthn-json` served as an ecosystem prototype of the functionality was [developed into the built-in browser methods](https://github.com/w3c/webauthn/wiki/Explainer:-JSON-Serialization-Methods). The built-in methods are compatible with `@github/webauthn-json` encoding, so you can use them as a drop-in substitute. We strongly recommend doing so, since:
 
-- The browser-native JSON parsing functions are increasingly receiving fields and features (such as user-agent hints and the `prf` extension) that `@github/webauthn-json` will never receive.
+- The browser-native JSON parsing functions are already available for the vast majority of users.
+- They are increasingly receiving fields and features (such as user-agent hints and the `prf` extension) that `@github/webauthn-json` will never receive.
 - Removing `@github/webauthn-json` from your codebase will remove code from your authentication pages, reducing load times for your users and reducing the chance you will need to debug issues.
 
 ## Fallback (not recommended)