brightness_pct is deprecated from scenes; what now?

[fermulator]

The problem

Per #33527 , it has become clear that brightness_pct is deprecated in scenes.

https://www.home-assistant.io/blog/2019/10/30/release-101/#breaking-changes

Scene - Scenes have to be configured more strictly from now on. Each entity must be configured with a valid state. Furthermore, the attributes that can be used must be device state attributes. This means that they should be listed under developer-tools -> states. - ([scene docs])

When I look at dev tools states, clearly brightness_pct is not listed.

So what is the equivalent replacement?
Why has it been deprecated and removed? (to be completely honest, this is a very annoying breakage of backwards compatibility) - I'd like to clearly understand the technical need or reason to "restrict scene states", for this trade off of functionality (there are a whole lot of other attributes lost...)

Brightness % is still a valid attribute for a light ...
https://www.home-assistant.io/integrations/light/

It is less usable if users have to compute a rough % themselves based on the 0-255 absolute value of brightness alone.

Environment

• Home Assistant Core release with the issue: 0.107.7
• Last working Home Assistant Core release (if known): pre 101
• Operating environment (Home Assistant/Supervised/Docker/venv): python venv
• Integration causing this issue: light entities in scene definition
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/scene

Problem-relevant configuration.yaml

example entry in scenes.yaml that worked fine before release 101

- name: Entertaining All Main On
  entities:
    light.main_floor:
      state: true
      brightness_pct: 100

Traceback/Error logs

Apr 02 07:21:34 hass hass[687]: 2020-04-02 07:21:34 WARNING (MainThread) [homeassistant.components.light.reproduce_state] The use of other attributes than device state 
attributes is deprecated and will be removed in a future release. Read the logs for further details: https://www.home-assistant.io/integrations/scene/

Additional information

Of course this particular example is specific to one thing. What about everything else for a light that a scene would clearly want to set or control? rgb_colour, white_value, etc

[balloob]

Use brightness. It goes from 0…255. Scenes work based on the state attributes, not based on the parameters you can pass to light.{turn_on/turn_off}

[fermulator]

@balloob , any chance there is a reference or explanation into why this backwards incompatibility was put in motion? Maybe some sort of technical reasoning?

"Scenes work based on the state attributes"

, this was not previously true, scenes worked fine before with "non-state attributes", and now being deprecated.

What about the other things like rgb_color, white_value, etc?

[fermulator]

This makes no sense still.

When I visit: https://www.home-assistant.io/integrations/light/

I'm still getting the deprecation warning. The "State Attributes" on the light still include both brightness and brightness_pct sooo?

[frenck]

light state attributes are not the same things as scenes.

[jackgray]

3 years later is this true? have I just spent an entire f&(*ing day getting gaslit that I didn't JUST CHANGE THAT SETTING

you mean to tell me that it is not reasonable to expect dimming the lights to be a "scene change"??? THAT IS EVERYTHING to a room