In one of my SharePoint environment, we had issue with my sites. When users click on about us, it automatically creates my site for all the user. All these my sites are created as a site collections in the web application.
We have 2000 people accessing the site and every user creating new my site. So it will be 2000 site collection in one web application. SharePoint can handle that, but we not using any my site features in our environment.
For this we just need to prevent the users to create my sites. We can do that from central admin site User profile service settings as shown below.
Open SharePoint central admin site User profile Service application. Select manage user Permissions.
We can see a popup as shown below. Select Authenticated users and uncheck “Create personal sites” option as shown the image below.
Click on Ok to save the settings.
Hope this will helps.