Repository: react-native
Issue: Performance Issues with React Native Bridgeless Architecture
Labels: Needs: Author Feedback,Needs: Repro,Type: New Architecture,Needs: Version Info

### Description

The **Bridgeless Architecture** in React Native 0.74 and later introduces significant performance issues, particularly for apps with complex logic and high demands for UI responsiveness. Here are the main concerns:

## Key Issues

### 1. Screen Load Times
- **Problem**: Synchronous communication with the native runtime slows down screen loading, particularly when multiple API calls are made.
- **Impact**: Initial loads are bottlenecked, reducing overall app responsiveness.

### 2. UI Responsiveness and Touch Lag
- **Problem**: The switch to synchronous communication impacts touch response, causing a laggy and less fluid user experience.
- **Result**: Reduced interaction quality and increased user frustration.

### 3. Lazy Module Loading
- **Default Behavior**: Bridgeless architecture loads modules lazily by default, contributing to delayed responses in complex pages.
- **Partial Fix**: Disabling lazy loading improves response slightly but doesn’t fully solve the underlying delay issues.

## Comparative Performance with Older Versions

- **Testing Results**:
  - **React Native 0.71.8** (asynchronous bridge): Modal with **32 API calls** loads in approximately **3 seconds**.
  - **React Native 0.74.x / 0.76.1** (bridgeless): Modal with only **14 API calls** takes over **10 seconds**.

## Attempts to Improve Performance

- **Native Threads & Configuration Adjustments**: Shifting API calls to native threads, and enabling/disabling options like **Hermes** and **New Architecture**, failed to yield significant performance improvements.

## Call for Optimizations

The **React Native community** and core team are urged to provide optimizations or alternative solutions to enhance performance under the bridgeless architecture. 

**Feedback Needed**: Community support and solutions for the architectural limitations causing these performance issues.


### Steps to reproduce

1. **Create a page/modal** with 10-30 API calls.
2. **Test in React Native 0.74.x** or later (Bridgeless).
3. **Measure load time** and UI responsiveness.
4. **Compare with 0.71.8** (Async Bridge).

Expected: Slower performance in the bridgeless versions.


### React Native Version

0.74+

### Affected Platforms

Runtime - Android, Runtime - iOS

### Areas

Bridgeless - The New Initialization Flow, Other (please specify)

### Output of `npx react-native info`

```text
System:
  OS: macOS 14.5
  CPU: (8) arm64 Apple M1
  Memory: 206.23 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.14.0
    path: /usr/local/bin/node
  Yarn:
    version: 1.22.19
    path: /usr/local/bin/yarn
  npm:
    version: 10.7.0
    path: /usr/local/bin/npm
  Watchman: Not Found
Managers:
  CocoaPods: Not Found
SDKs:
  iOS SDK: Not Found
  Android SDK: Not Found
IDEs:
  Android Studio: 2021.3 AI-213.7172.25.2113.9123335
  Xcode:
    version: 16.1/16B40
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.11
    path: /usr/bin/javac
  Ruby:
    version: 2.7.4
    path: /Users/santhoshkumarvgds/.rvm/rubies/ruby-2.7.4/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 15.0.0
    wanted: ^15.0.0
  react:
    installed: 18.3.1
    wanted: 18.3.1
  react-native:
    installed: 0.76.1
    wanted: ^0.76.0
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: false
iOS:
  hermesEnabled: Not found
  newArchEnabled: false
```


### Stacktrace or Logs

```text
The issue occurs when multiple API calls are made on initial screen load. The app becomes unresponsive and takes significantly longer to load the screen. Despite attempts to optimize by disabling lazy loading and using native threads, the issue persists. No crash or stack trace is generated, but the app's performance degrades considerably.
```


### Reproducer

Reproducer: Unfortunately, I cannot provide a public repository or Expo Snack at this time. Please let me know if you would like further details or an isolated example of the issue.

### Screenshots and Videos

_No response_