Create Managed Metadata Field not an Option in Tenant Site but all Other Sites Are Fine

Hi, this is very perplexing why creation of a new MMD field is available in all sites with similar path:

https://xxxxx.sharepoint.com/sites/xxxx/_layouts/15/FldNewEx.aspx?List=%7BB806FF8F%2D46AC%2D45BB%2D8D8D%2D1A8E2D7A8AF6%7D&FieldTypeParam=TaxonomyFieldType&DisplayNameParam=&DescriptionParam=&CustomFormatterParam=&VldFormulaParam=&VldMessageParam=  

But not in the, I assume main tenant site:

https://xxxxx-my.sharepoint.com/personal/cw_xxxxxx_ca/_layouts/15/fldNew.aspx?List=%7BA9B631FA%2D269D%2D4922%2D84C0%2DD8FAB0020562%7D  

even though you can see them in the Global Term Store on that tenant site.

I'm very confused. Shouldn't the Managed Metadata Field creation just be available period??

Thanks