To be honest, from my perspective the article/ review is very shallow, unbalanced and some findings are misleading. I probably tried 50 free gutenberg enabled themes, and from my view not one is as well done as Blocksy, not in a free version, and most of them not as a paid version.

Design and design options:
My impression is, that Blocksy stands out from the crowd with carefully designed elements (e.g. no clumpsy icons as most other themes), and the right options, to enable clients to customize their site to a design to make them stand out of the crowd too. A good example are the header and footer areas, where every row section and every element could be finetuned if needed. As it is top down structured in the customizer, there is no overload, and everyone only needs to step down the level he wants, that's fine.

Code quality:
What means "code quality"? Number of PHP files, extensive commenting? A much better and comprehencive analysis of code quality are the results with https://yellowlab.tools/, and there blocksy delivers good results in terms of clean and performant coding.

Discussing at length the additional entry blocksy companion is causing, is like to judge the qualtity and design of a new car on the fact, what kind of floor carpets are with it.

cheers