textTransform Capitalize Does Not Behave As it Does in CSS

Description

When using textTransform: 'capitalize' on a Text component in RN, if there are any characters after the first character in a given word which were already upper-case, they are then converted to lower-case. For example: "I am PSYCHED about react native" becomes, "I Am Psyched About React Native." When using CSS on the web, the result of applying the same property value on the same source text would be, "I Am PSYCHED About React Native," leaving characters which are already upper-case as they are.

This difference is observable both in iOS and Android simulators, as well as on an iOS physical device (an Android physical device was not available for testing).

I understand that React Native style props are not meant to be absolutely equivalent to CSS, but it is my understanding that the intent of the project was to create an environment which was as familiar to web developers as possible. And it sure would be nice if they behaved the same way in both environments.

If there are a significant number of users who prefer the RN implementation to the way it is implemented in CSS, certainly one solution might be to add another option for the enum (maybe "pure-capitalize," for example) so that developers could have it whichever way they like.

Version

0.64.3

Output of npx react-native info

System:
    OS: macOS Mojave 10.14.6
    CPU: (8) x64 Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
    Memory: 21.95 MB / 32.00 GB
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 14.17.6 - ~/.nvm/versions/node/v14.17.6/bin/node
    Yarn: 1.22.18 - /usr/local/bin/yarn
    npm: 6.14.15 - ~/.nvm/versions/node/v14.17.6/bin/npm
    Watchman: Not Found
  Managers:
    CocoaPods: 1.11.3 - /usr/local/bin/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 13.2, DriverKit 19.0, macOS 10.15, tvOS 13.2, watchOS 6.1
    Android SDK: Not Found
  IDEs:
    Android Studio: 2021.1 AI-211.7628.21.2111.8309675
    Xcode: 11.3.1/11C505 - /usr/bin/xcodebuild
  Languages:
    Java: 11.0.15.1 - /usr/bin/javac
  npmPackages:
    @react-native-community/cli: Not Found
    react: 17.0.1 => 17.0.1 
    react-native: 0.64.3 => 0.64.3 
    react-native-macos: Not Found
  npmGlobalPackages:
    *react-native*: Not Found

Steps to reproduce

Add the textTransform: 'capitalize' property to any Text component for which the source text contains an upper-case character in a word at some position after the initial character.

Snack, code example, screenshot, or link to a repository

Link to snack that reproduces the issue: https://snack.expo.dev/@duckandbeaver/texttransformnotlikecss

This MDN page shows how the similar property value behaves in CSS: https://developer.mozilla.org/en-US/docs/Web/CSS/text-transform

リンクされた Snack から始め、その Text コンポーネントの出力を、リンクされた MDN の CSS の動作と比較します。iOS と Android で Text のスタイル prop である textTransform がどのように処理されるかを追跡し、"PSYCHED." のような大文字と小文字が混在する単語のカバレッジを追加します。capitalize が先頭の文字だけを変更し、既存の大文字を両方のプラットフォームで保持すれば完了です。