I used a handheld CB for several years. It was convenient for talking between vehicles when we were travelling together. It was also nice when backing if the spotter had one. I would occasionally get information from truckers about availability of fuel, road closures, and traffic jams. It's not a necessity, but it was nice to have. I mounted an external antenna on my truck and connected the handheld to it using coax. I could plug the radio into the cigarette lighter. It didn't look pretty, but it was functional.
I used a Cobra 29 when I drove trucks. It had a weather band on it that I would listen to when there was weather in the area. It kept me out of trouble once when I avoided driving over a long bridge when a tornado was spotted.
I don't use one now and really don't miss it much. There seems to be a lot more garbage-mouthed idiots on the air than there use to be when it was regulated.