The “experts” really ought to do a lot of soul searching here. There weren’t good reasons to assume Russia was going to have an easy win a year ago - they just made several dumb assumptions and most “experts” went along with it. War is inherently unpredictable.
As a non “expert” (though I am a veteran and a professional military logistician) who is not humble enough to avoid tooting my own horn again and again and again, I’ll remind everyone once again that war is almost entirely about morale and logistics, and experts should have seen that Ukraine had a big advantage in both last February.