By default, WooCommerce places single-product summaries right next to the main product image / thumbnails section, which is ideal for displaying product descriptions, prices and meta. Add-to-cart forms are normally displayed inside the single-product summary, too, which works well when displaying Simple or Variable product forms.
However, this layout is not particularly suitable for complex product types, such as Composites or Bundles, which require much more space for their add-to-cart form content.
If you are having issues with very narrow or squeezed product add-to-cart forms, the WooCommerce Stacked Product Layout plugin can be used to move the add-to-cart form under the product image and summary section. The plugin adds a “Force Stacked Layout” option under WooCommerce > Settings > Products > Display, where you can select which product types should use the modified, full-width layout.