A WooCommerce store usually comes with full database access, a working REST API and a functioning CSV export. Compared with most source platforms that is a good position, and it is why the difficulty sits somewhere else.
WooCommerce stores products as WordPress posts with the commercially interesting parts held in post metadata. Anything a plugin added lives in that metadata too, or in its own tables, and it does not come out of a product export. Custom fields, product add-ons, bundles, role-based pricing, booking logic and delivery-date rules all behave like part of the product until you try to move them.
Variable products are the second theme. WooCommerce lets attributes and variations grow without limit, so ranges routinely arrive with more option dimensions than Shopify’s product structure holds. Resolving that is a business decision about how the range should be shopped, not a mapping exercise, and it is made before the import rather than during it.
The third is that the site is a WordPress site as well as a shop. Pages, posts, categories, tags, author archives and uploaded media all carry links and search visibility, and a plan that only accounts for the products will lose the rest.