I am not saying people search for sizes. I am saying people will not click a size 43 sock if they have size 36. But that might be a size that is available but just not showing up in the add... If there is no size shown or are dropdown people can see what sizes I have.
But I guess you only pay for clicks so it doesn't matter that much
Then you need to use an application for example mine, which allows you to exclude variant products and only submit the main product.