Yes, with some qualifications. I too see more people having problems with cap guns than with flint but I think that is because many casual, occasional shooters own percussion guns where as most flint shooters are more serious about their sport and more knowledgeable and experienced.
Also the gun itself is a factor. A cheap percussion lock may bust a cap as well as the best lock ever made. A cheap flintlock, on the other hand, can be a source of unending frustration. That is likely another reason we see more people having trouble with cap guns, they often are cheap factory built guns whereas flintlocksers often shoot more high dollar guns.
Then there is weather.
Assuming flint and percussion guns equally well tended, then in rain and snow a percussion is more reliable, especially after the first shot. Even strong, gusty wind can cause a flint to misfire and can make re-priming very difficult.
We here are a dedicated flintlock crowd but we should not pretend there are not good reasons why percussion guns replaced the flintlock about as soon as caps became widely available. There are many, many surviving muzzleloaders which have been converted from flint to percussion and I'm sure the owners did not go to that bother and expense for no good reason.
My own reason for shooting percussion after many years of flintlocking is that my hold has gotten so shaky I just can't maintain a solid follow through and I shoot better with percussion.
That doesn't mean I don't still enjoy my flint guns but when I get serious it is with percussion.
