On Android, you can hold the Torch icon in your notification panel to bring up a brightness slider

By default it's set to the middle: https://i.imgur.com/dtAv0rW.jpg

I do... Vividly, I was at Whirlowhall Farm on a school trip. I slept alone in one of the towers of the main building (or at least something I remember as being a tower, it tower-like) on the 2nd night and was terrified because we told ghost stories and went on a ghost hunt in the trees armed with Torches only

There was a tuckshop in a barn with a sliding green door...

The memories! - that was more than 20 years ago now... Lol

My first Smartphone didn't even have a light on it - when I used a Flashlight app it just turned my screen white and maxed out the brightness instead 😂