I use the notify service with a group platform. This way you add and remove devices in one place only. Here's how I set it up in configuration.yaml:

notify:
  - name: notify_all_devices
    platform: group
    services:
      - service: mobile_app_pixel_6_pro
      - service: mobile_app_pixel_3_xl

In my automation triggers, I simply call my notify_all_devices service.

After Hours (1985) by Martin Scorsese