Arguably a 16 gauge can adequately cover any hunting situation. Waterfowl & turkey were falling cleanly to high brass 16 loads years before 3" magnum 12 gauge hit the market. Slugs and buckshot loads are plentiful for deer. Plenty of ammo still being made by everybody! Many experts claim the 16 gauge is the perfect upland gauge when carried in a gauge-scaled gun. Browning makes the BPS in three 16 ga versions that can be had for around $500. Stoeger Condor is an entry O/U for $349-399.
CZ makes S/S and O/U's of good quality for a few bucks more.
Bottom line: I don't need a 20 or 12 gauge with a decent 16 in the gun cabinet.