While I agree with the first part of your statement, it doesn't follow that any of the pellet weights in the .20 ball park are any good for your particular rifle.
Similarly the OP seems to be alluding to the lack of choice being an advantage, which kind of fails miserably when the manufacturer of your preferred pellet either drops production of it or changes it.
Dies don't last forever and I'll bet there's less incentive for them to replace them when quality starts to fall off vs when they have to.