Having readable text associated with your link(s) is critical for users that use screen readers, in order to help them to easily navigate your site. These users are typically not using a mouse, and utilize a keyboard to navigate.
Screen readers often allow users to jump through available links on web pages. This means that links are often read outside of the context of the web page's content.
A link should therefore be able to stand on its own and allow a web visitor to know where it will go by solely reading the link's text and nothing else around it.
The need for having readable text with links includes both text, and alternative text for images. It is best to not use the same text for more than one link, as that poses an accessibility issue with making the website experience consistent for browsing.
Additionally, link text should not include the URL of the link. Screen readers will read each letter of the URL if it is in the link text. This could cause a cumbersome browsing experience for web visitors utilizing a screen reader.