Google's John Mueller was asked if the button attribute is treated like a link attribute. The answer was a straight forward, "no." John said on Twitter "buttons aren't links and don't inherently have urls attached to actions, so we wouldn't use them for crawling or otherwise."
Yes, there is a button tag or attribute, but it is CSS styling attribute. You can have a link attribute around it, and Google will then pick up the link. But you can also use a button attribute without a link and thus, there is no link for Google to crawl or for link signal purposes.
Seems straight forward...
Here are those tweets:
Buttons aren't links and don't inherently have urls attached to actions, so we wouldn't use them for crawling or otherwise.
— 🧀 John 🧀 (@JohnMu) October 15, 2021
Forum discussion at Twitter.