Can I use
?

Object.observe data binding

- UNOFF

Method for data binding, a now-withdrawn ECMAScript 7 proposal

Chrome

  1. ❌ 4 - 35: Not supported
  2. ✅ 36 - 49: Supported
  3. ❌ 50 - 141: Not supported
  4. ❌ 142: Not supported
  5. ❌ 143 - 145: Not supported

Edge

  1. ❌ 12 - 141: Not supported
  2. ❌ 142: Not supported

Safari

  1. ❌ 3.1 - 26.0: Not supported
  2. ❌ 26.1: Not supported
  3. ❌ 26.2 - TP: Not supported

Firefox

  1. ❌ 2 - 143: Not supported
  2. ❌ 144: Not supported
  3. ❌ 145 - 147: Not supported

Opera

  1. ❌ 9 - 22: Not supported
  2. ✅ 23 - 36: Supported
  3. ❌ 37 - 121: Not supported
  4. ❌ 122: Not supported

IE

  1. ❌ 5.5 - 10: Not supported
  2. ❌ 11: Not supported

Chrome for Android

  1. ❌ 142: Not supported

Safari on iOS

  1. ❌ 3.2 - 18.6: Not supported
  2. ❌ 26.0: Not supported
  3. ❌ 26.1: Not supported

Samsung Internet

  1. ✅ 4: Supported
  2. ❌ 5 - 28: Not supported
  3. ❌ 29: Not supported

Opera Mini

  1. ❌ all: Not supported

Opera Mobile

  1. ❌ 10 - 12.1: Not supported
  2. ❌ 80: Not supported

UC Browser for Android

  1. ❌ 15.5: Not supported

Android Browser

  1. ❌ 2.1 - 4.4.4: Not supported
  2. ❌ 142: Not supported

Firefox for Android

  1. ❌ 144: Not supported

QQ Browser

  1. ❌ 14.9: Not supported

Baidu Browser

  1. ❌ 13.52: Not supported

KaiOS Browser

  1. ❌ 2.5: Not supported
  2. ❌ 3: Not supported

Support in Blink-based browsers is expected to be removed in future versions.

Resources:
Firefox tracking bug
An update on Object.observe
Polyfill
Data-binding Revolutions with Object.observe()