After the collapse of AGC, and AGN being cut off and later surrounded, about half of Germany's A-team (such as it was) suddenly wasn't there to speak of.
So they started pouring almost raw recruits, old men, boys, anyone who could do the job basically, into the front lines to try and put something in between the Soviets and the rest of Germany.
Basically after Bagration, the Germans lost any ability to operate and respond on a strategic level, forcing them into more and more reactive, ad-hoc action.
Ancillary to this is the fact that they were monstrously outnumbered, especially in terms of tanks. At the end of things, some of the "Panzerarmiees" OKH was ordering around had less than 50 operational tanks
And lastly, logistically the Germans were utterly fucked at this point. Allied bombing was finally able to cripple their transport infrastructure, lack of fuel kept trucks off the road, and river canals only go A to B.
Ammunition for everything but the rifles was short as hell, and nobody trusted they'd be able to get more rifle rounds tomorrow either.
In short, in 1945, German forces mostly consisted of old or young men with minimal training, little in the way of heavy equipment, virtually no tanks or artillery, effectively no airforce, and transportation mostly consisting of horses, fighting 4:1 against the two best equipped military forces on the planet, and in battles where local success was already overshadowed by strategic failure.