Be careful when using semantic elements purely for presentation purposes. For instance, the <aside> element gives the element a landmark role 'complimentary' telling assistive devices that this is not part of the main content.

That's not really true for your cards, though, they are part of the content.

Also, having multiple complimentary landmarks in the same context (main, footer) is really confusing. Having 3 <aside> elements next to each other would be like having three <header> elements next to each other.