In their present chamberings, kinda, but no self-loading gun is truly obsolete. However 80kpsi and some grip geometry optimization permit the feeding of an intermediate cartridge through the grip, so the mag-in-grip architecture is nerfed given what’s possible.

Picrel is something I sketched up. It is meant to be the cross section of a grip at the point where it interfaces with the web of your hand - the point of smallest circumference. 1” in width, 2.15” in total depth. The red lines are the outline of the magazine (1mm thin). The outside of the grip is nice and curvy so shouldn’t be uncomfortable. Cartridge overall length is 1.8”, Case head diameter is 0.39” (10mm - same as 9x19mm). The Bullet is .257 in caliber and 0.9” long (optimal for maximizing retained energy at 300yds from 8” barrel, but anything from .243 to .264 works equally well). At 80kspi, the powley computer tells me this should produce 1100ft*lbs from an 8” barrel. Closer to 1300ft*lbs from a 12” barrel, but that’s getting a bit long.