I agree that there are too many out there for .40 S&W to become obsolete. I only have one myself, a KP944, which is the first Ruger semi-auto centerfire I ever owned. Bought in 1997, IIRC. Good grief, it just hit me that I've owned it 25 years now! I think I need a moment... I know that some folks have no love for the original Ruger P-series, but I get along well with mine, and am reasonably proficient with it.
I brought a new Max-9 home this past weekend, and ran 50 rounds through it Sunday afternoon. Really liking it so far, but if Ruger offered a "Max-40", I would have bought that instead. Have considered an SR-40C (which do not seem difficult to find at reasonable prices), but would like something a bit slimmer as a CCW.