It is also worth noting that by 1944, the Germans had developed or were in the process of developing potentially war-changing technologies; including the following:
Jets: obtained a 4:1 kill ratio against enemy aircraft.
Wasserfall: a guided surface-to-air missile capable of helping defend Germany’s skies
Type XXI U-boat (in development in '44): a very quiet, stealthy, highly advanced submarine difficult to track or kill. It had advanced electronics, allowing it to hunt and kill enemy ships without being detected. It used electrically powered torpedoes that did not leave telltale bubble trails.
Panzerfaust: a shoulder-launched rocket used to destroy enemy tanks. Easily produced and effective.
Panther tanks: significantly better than their Allied counterparts.
If in 1945 Germany had gone to war with a mostly jet air force, with a tank force consisting largely of Panthers, with infantry equipped with Panzerfausts and other advanced weapons, and with production capacity at or above the level it had historically obtained in '44, it would have been very difficult to stop.
Add that to the very unlikely, but not impossible prospect of Hitler persuading Japan to not attack US in 41, but instead building up, and sending lots of forces to Siberia, not necessarily to fight the Russians directly, but for tying up Russian resources which would be desperately needed on the eastern front.
There are many ways that the history could go in other directions instead of our known history. Imo, determinism is an illusion.