>>3087380The point is ultra wide on APS-C. If you don't need wide or ultrawide, go for >25mm lenses, they're sharper.
Also equivalent FF / MF lenses are sharper. So if you want the sharpest possible wide angle shots, pay up for the higher end of FF / MF lenses.
Either way, a Pentax-M 28mm isn't outresolving a 12mm Samyang f/2 *regardless* of it being not a match for modern normal to tele lenses.