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Method for data binding, a now-withdrawn ECMAScript 7 proposal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 - 155: Not supported
  4. ❌ 156: Not supported
  5. ❌ 157 - 159: Not supported

Edge

  1. ❌ 12 - 154: Not supported
  2. ❌ 155: Not supported

Safari

  1. ❌ 3.1 - 26.6: Not supported
  2. ❌ 27: Not supported
  3. ❌ 27.1 - TP: Not supported

Firefox

  1. ❌ 2 - 158: Not supported
  2. ❌ 159: Not supported
  3. ❌ 160 - 162: Not supported

Opera

  1. ❌ 9 - 22: Not supported
  2. ✅ 23 - 36: Supported
  3. ❌ 37 - 134: Not supported
  4. ❌ 135: Not supported

IE

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

Chrome for Android

  1. ❌ 156: Not supported

Safari on iOS

  1. ❌ 3.2 - 26.6: Not supported
  2. ❌ 27.0: Not supported
  3. ❌ 27.1 - 27.2: Not supported

Samsung Internet

  1. ✅ 4: Supported
  2. ❌ 5 - 29: Not supported
  3. ❌ 30: 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. ❌ 156: Not supported

Firefox for Android

  1. ❌ 159: 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()