Failed search.
Is there a device you can buy that can supply power to multiple 12 V DC devices? Maybe, but it’s hard to find.
20180511/DuckDuckGo 12 v dc power supply to multiple devices 20180511/https://electronics.stackexchange.com/questions/245689/multiple-12v-devices-with-one-power-supply
This is an interesting site.
20180511/https://www.circuitlab.com/
This site has way too many advertisements.
20180511/https://www.edaboard.com/showthread.php?194820-12v-dc-power-supply-with-multiple-devices 20180511/https://electronics.stackexchange.com/questions/149931/does-it-make-sense-to-power-multiple-12v-devices-from-one-single-power-source
Only “universal” power supplies with one voltage output are being advertised.
20180511/https://www.amazon.com/slp/multiple-device-power-supply/sstkwu2sofcf4jp
UPDATE 2019-12-04: See my next blog post for the answer, which is simply “yes” for low-current applications.