I have several years now flying RC planes and have around ten flyable planes all of them have their own fuel filter. Because of the time I can tell you that this inexpensive part will not hurt your economy and can save a good reliable engine or carburetor from working at its top.
Depending on the usage of each plane I always clean the filter once in a year, sometimes they are quite clean, sometimes they are not, and I have found some particles that in my thoughts could cause an unexpected behavior of any engine. Some other people at the fields I use to go just do not seem to be worried about the use of this cheap part but as I said it is that cheap that there is no reason for not use it.
Actually our cars and trucks that we are driving have at least two filters, one at the pump and one more at the line that goes to the injection assembly, Why?
Well because of the fact that the performance of any engine is always related to the quality of the fuel.

Regards

Alfred