I have a poor understanding of electrical engineering so I am not sure this would actually work. But I've wondered if one could make a fairly cheap gadget for turning a decent USB-PD supply into a somewhat useful hobbyist variable voltage DC power supply.
Especially with USB-PD 3.1 which has an adjustable voltage supply mode [1] so you are not constrained to only a handful of power profiles. I think in theory you could offer 5V, 9V, and 15-48V.
It would be cool because it would be much easier to carry (keep in your backpack) and I imagine cheaper than a benchtop power supply so long as you have access to a capable USB-C charger. But I'm not sure what you'd be missing out on versus a proper benchtop.