For a couple of reasons. One, my CHCL expires in Oct and must be renewed. (The State sent me this info last week) and two, reference,
https://www.ark.org/asplicense/chcl_application/chcl.aspx
If you are correct there are a lot of folks in AR that are getting ripped off for unneeded application and renewal fees.
As with all the other states that have gone to constitutional carry since 2005, Arkansas has retained its concealed carry permit system. The permit gains reciprocity with a number of other states. In most states the permit allows people to buy guns at dealers without going through the instant check system.
Arizona, where I live, still has a concealed weapons permit, and I maintain one, even though none is needed to carry concealed.
There are good reasons to keep the permit system in place, but because it is there, that does not mean one is needed to carry concealed legally.