That aspect of the user interface is not something that is under the user's control. Only Apple could make that change. To have Apple consider your feedback, submit it here:
Feedback - macOS - Apple
Your choice of background wallpaper does influence the readability of the menu bar. Go to System Settings > Wallpaper and try some of the options, one may be better than others. There are solid color options if you scroll to the bottom.

More info: Wallpaper settings on Mac - Apple Support
Here are two examples from different Spaces on my Mac, one where the background is light and another where it's dark green. The macOS battery icon is on the left, note that it changes color based on the wallpaper. I find the black icon with the white text harder to read, thus my suggestion above about wallpaper choice.


Another option may be a 3rd party tool. Personally, I usually have the macOS battery menu bar item off, and I use iStat Menus to show that information. That is in the center of the screenshots above, with a customizable display (I have different colors for charging, full, discharging, low, etc.), and the status is show in text next to the icon.