How much SEO damage would it do having a subdomain site rather directory site?

[GastonRiera]

Hi all!

With a coleague we were arguing about what is better: Having a subdomain or a directory.
Let me explain some more, this is about the cases:

• Having a multi-language site: Where en.domain.com or es.domain.com rather than domain.com/en/ or domain.com/es/
• Having a Mobile and desktop version: m.domain.com or domain.com rather than domain.com/m or just domain.com.
• Having multiple location websites, you might figure.

The dicussion started with me saying: Its better to have a directory site. 
And my coleague said: Its better to have a subdomain site.

Some of the reasons that he said is that big companies (such as wordpress) are doing that. And that's better for the business.
My reasons are fully based on this post from Rand Fishkin: Subdomains vs. Subfolders, Rel Canonical vs. 301, and How to Structure Links for SEO - Whiteboard Friday

So, what does the community have to say about this?
Who should win this argue?

GR.

[Alick300]

Hi Gaston,

Check this debate including Rand Fishkin @ https://inbound.org/blog/the-sub-domain-vs-sub-directory-seo-debate-explained-in-one-flow-chart

Thanks

[GastonRiera]

Hi!
That's a great article and the comments are highly valuable. The statement they say is that it depends on the content.
They push you to increase the efforts on content rather than in a small change like this.
Do you agree?

Personally it feels for me that both should be important, the content and this SEO thing.

[LoganRay]

There are a few good use-cases for subdomains; higher education sites use them frequently, and often have organizational need for it. Another instance I can think of is international websites that want to have different sites for each country in which they operate. This can help each division operate a site without having to go through HQ every time they need an update.

That being said, given the typical website, with SEO considerations, I always favor subdirectories for the simple reason of keep all domain metrics (links, authority, etc.) together, rather than splitting the metrics across subdomains.