Take three dead 2018–2022 laptops.
Remove batteries, link them with a $9 Thunderbolt cable or $15 Ethernet switch.
Run Proxmox or Ubuntu cluster — instant 36–48 core beast.
Beats a $4,500 Mac Studio in multi-threaded work.
Real example: user turned three Dell XPS 9570s into a 4K video renderer that finishes jobs 4.5× faster than single machine.
You already own the parts.