Apple Watch 10 too dim in low-light conditions

Did you make sure, that you adjusted the brightness in the general settings?

Adjust brightness and text size on the Apple Watch display - Apple Support

This user changed the Accessibly settings for minimum brightness to get a brighter display:

Apple Watch display dim after upgrading t… - Apple Community

If you increase the brightness, will this issue persist?

If you want to give this as feedback to apple do so using this form Product Feedback - Apple