Man, I spent a lot of time looking for something like this when i bought my NAS and got annoyed with all the power bricks. Guitar players use them[0] to power their several guitar pedals, but the polarity, voltage and plug form factors are all the same, as far as I know. The various devices i have use slightly different plugs, polarities and i think not all are 12VDC.

I'm very surprised that nothing like this exists in the tech/IT space. There can't be that many form factors, voltages, etc. to deal with.

[0] I think something like this: https://www.monoprice.com/product?p_id=600062