One pretty popular home alarm brand uses I2C as “the bus” with somewhat ridiculously large cable lengths for what was designed as a board/enclosure level cheap serial bus. It is in no way a sane design, but it seems to work.
This reminds me of one of the dirtiest things I've seen in this space. Saw i2c buses bridged across multiple chassis by bridging the boards with CAN transceivers. It mostly worked, but I feel like everyone who signed off on that design review should feel bad about the atrocity they created.
