I've never used a dark mode on anything. Just less brightness is all I need.
There are some people that prefer to lessen their phone brightness. Also some people will put it on 'eye care' at night which can filter out the blue ray light which is what that is affecting the eyes but it can make some sleep faster. I have tried all but dark mode is better in the night than to just reduce the light.
There was another browser which were two on Android that has good dark mode. If you search for Aloa, you will see the two of them. They both have good dark mode.
If you want to stick to chrome, read what Wonder Work posted above.