In reply to Nick.

Hi Nick, as the author of the Hansen theme, part of my thought process when creating the theme was to highlight issues such as you describe. I'm glad you brought this up because my hope was and still is that greater minds will find solutions to address the issue of layouts in patterns being changed/broken when switching themes. Apart from the custom pattern classes, the theme now works pretty well with the stylesheet removed, thanks to the progress being made with Gutenberg. For my next block theme I am aiming for an empty stylesheet, with fully 100% of the CSS rendered by Gutenberg/core.

I do have to disagree about being locked in however. Design/layout lock-in is not the same as content lock-in. With theme patterns and the custom styles that may sometimes be found in these patterns, the user's content is not lost when switching themes which would be the case with custom blocks or shortcodes. The content is still present*, only the design/layout may have changed. *The exception is images in patterns but it is expected that the user will change the placeholder image for one of their own.

I am reasonably certain that custom blocks will not be allowed in themes submitted to the official themes directory. Not right now anyway. If at some point in the future it was possible for custom theme blocks to be retained when switching themes, I could see this rule being reconsidered, but I'll admit I don't know if this is or will ever be possible.

To your last point about the confusion of so many options. I see this as a good thing. WordPress design will become much more democratized like never before. If a user wishes to create an ugly design, that is their right to do so, even if it is in the pursuit of creating a beautiful design. It is right to let users have this option. There will be entrepreneurial designers with the flair to design a great site without necessarily needing the coding knowledge that may have previously been a barrier.