I agree with you the free shipping modules could be improved, such as the USPS module and so forth.
It would be really great to have official TB versions as well, at least for the main shipping carriers.
However, to be fair, Shopify charges a monthly fee to simply use their platform at all, and woocommerce doesn't even offer free domestic USPS calculation anymore. My understanding is, as of later last year unless you're a preexisting shop (which were grandfathered in), they now request you to pay $79/year. I have a grandfathered in shop that calculates for free, but I opened up a different, new shop on woocommerce earlier this year, and at the moment, all I can even offer is flat rate shipping on there, because woocommerce doesn't give me any other functionality.