The color contrast for links can be improved especially with dark mode, light blue on gray is difficult to read! Normal text has good contrast with white on gray, but the links are a problem for the eyes!
Links have high contrast to read easily
Links have low contrast similar to background color
The link color was changed to blue here:
While the links are difficult to read in dark mode under normal conditions, they are really impossible to read if you are in a setting with bright light (outdoors in the sun) or if you have the screen dimmed.
I was reminded of this recently when I wrote a phone number in a message to a friend. I wanted to read the number again to double check I sent the correct number, but the phone number was automatically converted to a link and with the low color contrast of blue on gray I could not read the number at all without bringing my phone very close to my face. But obviously this is not great UX! I could read all the other text in the message and the UI elements without any problem, only the phone number which displayed as a link was unreadable.
I expect that some user testing with the colors and readability of links would confirm this is a usability issue.
Switch to dark theme
Dim the screen or go outside in the sun
Write a message with a link or some text which will convert to a link
Try to read the link
I regularly use devices outside in the sun. I turn the backlight up and switch to a bright, high contrast, almost monochromatic color scheme to facilitate this.