It bears pointing out that as armor improved, the increasingly large and expensive to produce sword fell out of
general favor as battlefield weapon. Against mail, the one handed swords were already ineffective slashing weapons and plate armor took away most of its offensive ability altogether.
So the sword became a relatively massive piece of steel wielded in a brutal two handed fashion, every inch of the piece being transformed into a purposeful weapon, from the point to the pommel, with the tactics to match. The "dirty" two handed sword fighting today's enthusiasts realistically portray from fighting manuals from the day were from the apex of the sword as a battlefield weapon, but by then, affording multiple examples of such swords, as well as the heavy armor required to make up for the loss of a shield to use as a defense was becoming prohibitively expensive for all but the well to do upper crust.
Knights and men-at-arms were practical and as interested in surviving their battles as much as any modern warrior. Practicality and cost effectiveness also colored the judgement of the nobles who paid to equip and field armies or mercenary forces as well.
An entire array of cheaper to produce, and brutally effective, axes, maces, flails, hammers, and pole arms became the weapons of choice in the later Middle Ages for most run of the mill infantry troops and knights, until effective gunnery saw the end of the plate armor and the renewed popularity of the sword as a "sidearm" to a slow to reload firearm rather than a residual symbol of high standing.
It would really be interesting to see a TV series where these weapon and armor combinations were pitted against one another realistically. I would be curious to see the heavily armored knight with the two handed sword taking on a moderately armored knight using a shield and a small headed hand axe with a back spike. Equally scary propositions would be my bet.