A hard deadline concentrates minds. Whether that deadline is the end of 2020 or the end of 2021 doesn’t alter that fact.
The shape of the deal, the three sticking points have been know for months, the only thing missing was the UK or 27 other nations deciding whether to move or not. Again, this would have played out the same 12 months from now, the only real difference would have been the absence of a pandemic which has put more pressure on the UK side as we have more to do, preparation wise, and the pandemic has hampered that preparation.
Not securing the additional 12 months extension was a failure of the UK state and has caused additional tensions between ourselves and European countries. The inability to see this is symptomatic of the myopia that infects UK politics.