Improper usage for tags is problematic for Google

Published: January 17, 2019

Yes, having an incorrect href implementation for your <a> tags may lead to Googlebot not being able to discover URLs and content on your website.

When you build links to internal pages on your website, make sure that:

“Links have an href attribute pointing to a URL, so Googlebot can follow the links properly” source

If there’s no href, Google might miss the links and your pages will not be indexed.