Hey
@hedlnd, Glad to know that you are happy with your Zenfone 9 purchase. I've forwarded your suggestion to the team.
Now, as for the lack of such a feature, the reason is that if the screen lights up for a longer duration, it will severely affect the battery life of your phone. However, you can probably try adjusting the brightness of your phone to Adaptive brightness, it may help resolve the dimness issue that you experience in daylight.