In all example circuits using a transistor to power something (say, a motor), it seems to always be an NPN transistor (or NFET) with the something/motor connected to V+ and the collector/drain.
This leaves the powered component ungrounded, connected only to V+ while not powered. So (in the case of a motor) the ungrounded chassis cannot touch any other ground. So if its mounted to a grounded frame, next to another motor perhaps, turning one on will turn on both, so they must both be isolated and be sure no ground can touch the motor’s ground.
Am I missing somthing? Is this really how circuits are designed or is there something (multiple things) basic examples omit for simplicity? Do I just need to get over this and accept a less-than-ideal world where everything doesn’t actually work the way I wish it did?