Ever since my faceplate circuit board on the radio stopped working, the car's alarm & key won't be recognized (everything worked fine the day before the faceplate broke)

Car still starts but the gauges vibrate from time to time, and the red key icon on the dashboard lights up for a few seconds. The keyless unlock/lock do not work. I followed the steps to reprogram the key but it won't work.

My question is, what does the faceplate/radio have to do with the key/alarm system? There are many people that seem to be replacing the factory radio & faceplate with Metra kits. Is this common?

Maybe I'm better off buying an aftermarket radio & faceplate?

Thanks.