Commoditized doesn't mean 0 capex. Literal commodities can in fact be very capital intensive (ex. offshore oil rigs).

In this case, you need capital to stockpile the GPUs.

I've put some of my savings in commodities (mines, etc).....

If ASI and the ability to build robots becomes generally available and virtually free (and if the exponential growth stops), the things that retain their value will be land and raw materials (including raw materials that contain energy).

For the physical infrastructure that the AGI (and world population) uses. Capital will still be needed to purchase finite land and resources even if all labour (physical and services) is replaced.