[dnlzro]

Whether it is a bad idea for usability depends on what you are trying to accomplish. For example, Matthew Butterick's online book Practical Typography styles links so that they are not highlighted or underlined in any way. Instead, they are instead followed by a small red circle [1]:

"Vigorously styled hyperlinks on a page tend to move to the foreground of a reader’s attention, like an HDTV in a hotel bar. [...] The red circle is meant to be noticeable while you’re reading the sentence that contains the link. Otherwise it disappears, so as not to distract."

[1] https://practicaltypography.com/how-to-use.html