they do wear a little over time and thats part of their job, if you dont have a bushing or something on the stub your strut or stuffing tube would be the parts wearing out which would be more costly and time consuming to fix
notice the strut on this boat has no bushing or stuffing tube in it, just bare aluminum

same strut with a bearing and stuffing tube in it the brass bearing is hanging a little out of the strut in this picture

I would get you some better pictures but cam program isnt on this computer yet

one thing to remember the fit and finish of stock RTR parts isnt always great and aftermarket to stock parts fit and finish isnt always a perfect match either, Not saying the RTRs are bad just the opposite, they are the perfect learning tool in RC as they make people learn how to fix problems and 90% of everyone tears them down and modifies the crap out of them which is a big step on the way to custom builds and higher end RC if one chooses to go that route. Just like now, you are learning your drive-line which carries over to