Run a lightweight Linux distro on older hardware maybe?

Exclusively using a ever dwindling stock of old hardware is not really a practical solution to preserving hardware rights in the long term

The future is ragged shoeless and grimy humans fighting over the last few 1990's pocket calculators.

This is it. Buy used Dell and HP hardware with 32 GB of RAM and swap the pcie ssd for 4 TB.

No, this is not it. It only worked when there were a small number of buyers for used hardware, who were largely enthusiasts. The moment it becomes mainstream you're going to face the same scarcity in the used/refurbished market as well.

There are lots of such computers to be repurposed. It'll relieve price pressure and avoid e-waste.