As McAlister says in the video, it’s easy to make a block theme in the editor, but he’s aiming to make a theme as a product which is robust and coherent from end to end. He notes that making a theme like this is now MORE difficult, because of the complexity of theme.json and the various component parts.

That’s a perspective from a small business selling a theme to thousands of people, but this experience is mirrored for any small dev business creating a bespoke theme/plugin package for a single client. In that case we’d also need to make sure all the new FSE complexities are handled, we need to add help tips for the staff who will use the site day to day. We need to modify the admin interface to reflect client work practices, add bespoke functionality and hide some features depending on role, etc.

Those concerns he mentions which relate specifically to the complexity issues of a bespoke FSE experience are felt outside of the Theme-seller industry and have massive impacts for the “making WP sites for clients” industry

I feel that FSE and Gutenberg are driven by academic aims toward academic targets. For example: the concept of “Intrinsic Design” seems completely logical and sensible, but in the awful messy real world we make complex sites based on client needs. The disparity between what seems academically correct and what is actually needed IRL is worlds apart.

Trying to implement client requests for bespoke behaviours on short deadlines is far harder in the “New” WordPress. The old WP saved me time in those crucial crunch areas and became an invaluable tool, whereas the new WP causes me massive anxiety and cost in those moments.