My ender 3 v2 extruder is crushing the filament and snaps thus the printer fails to print. I have adjusted the extruder tension, nothing has changed. I also upgraded to a 0.6 hardend steel nozzle and I checked if it was the nozzles temperature, that made no difference.
First, I don't think it's the extruder crushing it, I think your filament is brittle.
Whenever you bend PLA (e.g. unroll it from the spool, or even worse, run it through the bowden tube, it develops microcracks.
In the space of a few days, these cracks make the filament super brittle.
Before loading the filament, take the loose end of the filament and bend it a bit. If it breaks like spaghetti, that part is brittle due to these cracks. Keep going until you reach a part that you can bend by almost 90° without it snapping. Break/cut it off at that point and load only the non-brittle part of the filament.
Did you maybe "release" the extruder spring tension adjustment screw in the wrong direction? (Maybe screw that screw to the limit in the other direction and check if that removes the issue)
If that doesn't sove the issue, there are only two possibilities:
Your extruder is assembled wrong. Disassemble and reassemble it, following a decent video.
Your spring is far, far too strong. This would be weird. That would mean they put the wrong spring into your printer.