It is worthwhile mentioning that the Airbus A320 wing was designed 35 years ago for a 70t platform, and has remained the same on all versions, from the A318 through to the A321.

While unchanged, the wing has seen a steady loading increase: to 83t on the first A321, then 89t and 93.5t, and is finally expected to go up to 101t on the A321XLR. This increased wing loading has meant higher take-off speeds, reaching close to the maximum tire speed limits, and a lower safety margin at altitude – in other words, a tighter “coffin corner”, and lower stability protection.

Airbus just hasn't had it's day yet.