As far as who thought it would be an easy war to win, that appears to be Putin's folly. The "Biden" regime did nothing to impede it when war was imminent and was ready to write-off the whole country after a few days when they offered Zelensky a ride out. The West was as surprised as Putin by the tenacity of Ukrainian resistance and basically shamed into providing niggling support. And two years later and even after months of supply shortages the Ukrainians are still fighting well and forcing Russian advances to a crawl. The Russians attacked Terny for 4 months, lost 100+ armored vehicles and having exhausted reserves in that sector, the Ukrainians took 1.5 km back. Novomykhailivka is littered with the carcasses of 300+ Russian vehicles and thousands of Russian corpses.
As far as training goes, Western training assumes conditions for maneuver warfare, especially functioning air forces and capable combined arms, things of which neither side is capable. Using armor piecemeal against entrenched defenders behind minefields would have been a fool's game even in WWII. Everyone (including the Russians) expected fast movement reminiscent of WWII or the Gulf War, but both sides got the Somme instead. Shortages are simply failure stemming from lack of investment in productive capacity which will be slowly remedied, and the West (like Russia) has reached out to allies like SK for additional munitions. And Russia's conventional artillery advantage is less than it seems (even with the FABs) when I've watched a Ukrainian command center with 5 or 6 guys and several FPV drone posts with a similar number each slowly and methodically hunt down almost all the vehicles and men of a Russian company: they're too dispersed and hidden to be easily targeted by artillery.
Well, the Russians have FPV drones too, but you usually don’t hear about those successes on Western TV. I watch the Military Summary Channel and Alex Mercorius, who is fair but certainly likes to see the Ukrainians lose. Russia is now on a military foothold and military production has increased incredibly. Plus, they have ties to N Korea for shells. On the other hand, Ukraine has a shortage of shells and wants shells quantities that nobody can provide. It needs men, trained men (not conscripted men from press gangs), it needs an air force, it needs more missiles, it needs more money, and most importantly it needs a plan. Everybody was too confident at the beginning that the Russian would lose and roll over. Ukraine had a chance for peace at the Istanbul talks, but Boris Johnson convinced them to go to war with Russia. And the sad thing is, Zelinsky is now like a delusional person, not realizing the mess he is in. He’s almost like Hitler in the final day: nationalization of the country with women and children on the front lines, belief in a super weapon that will win the war (Germans believe in the V2 rocket and Ukrainians believe in the F16 jets), no compromise or talks with the enemy, the Arian SS purity as you now see with the AZOV brigade; and I could go on with these parallels. But it all results in the massive death of your country men.
The Russian have not started their offensive but have waged a war of attrition on the Ukrainians, a meat grinder tactic. I think they are preparing for their offensive that will come sometime between May and August (Zelinski will legally not have power after May 29th because there were no elections). Now there are missiles and bombing attacks of train stations, airplane runways, power plants, etc., in the interior. That will soften the Ukrainians up. As well, more Russian soldiers have now reached the front lines and that is a sign of things to come. The Ukrainians have no plan but to die or pull back. And from what you hear from Russia government, more Ukrainians are dying than ever before. There has even been a Ukrainian brigade surrendering because they were told not to retreat and that meant certain death.
So we can believe what we want, but I think Ukraine is in a Hellhole. I think their army will snap, and it may come pretty soon.