Quite frankly, the issues with the kubel are the same as they had been (still) for ages with maxims:
None of the stationary MGs save the maxim ever hits the field in a manner that can keep time with enemy unit production. By the time the other mgs have hit the field, there are as many or more enemy units to advance and flank it.
Not so with kubels, and not so with maxims. Maxims have been heavily reduced from their former glory, but still, they have always been able to suppress a unit, and rotate to suppress a flanking unit before the first unit has recovered.
This is why maxim spam is so powerful, because the initial maxim can handle its own long enough until the next ones arrive to completely lock down the area.
Kubels were ridiculous in that they could chase units AND suppress them, as well as rotate and reverse to take on any number of advancing threats. Where a maxim (alone) can eventually be overwhelmed, a kubel really never was until a literal hard counter hit (if ever the game lasted so long.) It appears that they still can, but their their ability to suppress on the move is gone which was very much a blatant problem.
Honestly, I feel like the kubel should've has all it's suppression removed and kept it's damage, but that's because I miss jeeps and bikes. Those units and the roles they played are one of the many components and mechanics of the CoH franchise that seem to have been purposefully omitted from CoH2.
