According to a Google video, they perceive and treat subdomains and subfolders equally. If you want to do the work of building out the separate entity profiles and the link value for the multiple subdomains, then go right ahead. Google really doesn’t care whether they rank subdomains or subfolders. If you feel that you're maxed out on time fully optimizing one domain, let alone multiple domains, then subfolders are probably a better option for you.

Key Takeaways:

  • Most companies only have one dimension and it isn't necessary to have multiple subdomains that are treated like separate businesses.
  • The subfolder instead of subdomain approach creates less brand dilution and is easier to manage.
  • Since subfolders take less work to manage, you are more likely to keep the content fresh, which leads to better Google rankings.

“Each subdomain basically functions as a separate “business” within the overall corporation. When subdomains are used in this way, they can be very successful for obtaining great rankings. Each subdomain stands on its own and may or may not be linked to from the main entity.”

Read more: https://www.searchenginejournal.com/subdomains-vs-subfolders-seo/239795/