Even if the AI frontier becomes "totally commoditized" it will still be reliant on a scarce factor, namely leading-edge chips. Chipmakers will ultimately capture that value, because competing it away would require expanding the industry and that's a very slow process involving billion-dollar expenses planned far in advance (multiple years, and that lead time can only expand further as the required scale gets even larger).

You don’t think open AI models will eventually be able to design and build chips and fabs and all their components?

Except you're neglecting the fact that LLMs can become more efficient.

The magical thing about software is that efficiency gains can come pretty quickly relative to other industries.