Berdan cases are harder to reload - but Berdan primers are far easier to make.
Its far easier to reprime a Boxer Case than a Berdan case, true enough. Provided you have Boxer primers.
Consider that it is far easier to make a Berdan primer than a boxer primer. Its just a percussion cap. You don't have to clean out a tiny used primer and handle an even tinier anvil. Seems to me that if you are making your own primers as part of the reloading process, Berdan Cases would actually be overall easier to reload.
I suppose the only reason this has never caught on is that ther eis no simple and easy way of getting the Berdan primer out