Poor SWR can drop the signal by 1/2 or even more and CAN damage the transceiver.
Thru the glass units on CB frequencies drop the signal by at least 3db (1/2 or more). However assuming proper SWR they are fine.
The problem with SWR tuning is that USUALLY there is no method with the transceiver alone to measure and adjust. To be sure, you have to get a piece of test gear, or have a shop check it for you. Due to all of the places an antenna can be mounted, the type and size of vehicle, etc. Buying off the shelf and mounting is just a crap shoot as far as SWR goes.
The good side. The 4W output (usually less) and relatively robust output transistor(s) means you will get typical crummy performance but won't hurt anything
. (and for $49 who cares?)
If you want it for communications with your traveling mates, get a pair or more of "Family Radio" units (FRS). Transmit range is 3 to 10 times more. NO NOISE at all. No wiring, no external antenna. (Plus it is great for backing into spots, trailer hookup etc. Your helper uses one to talk to you.) FRS is one of the first things I got for my RV.
Several smart phone aps are available for traffic, weather, even speed traps. CB is mostly for entertainment (if that entertains you.)
Ham radio is obviously the cream of the crop, but licensing and lack of use for highway communications, (except for between hams) makes it somewhat not useful.