While 6B and 6A nerfs are questionable, let's not forget that CT/CS1 Ragna needed those strings, specially considering that his A's moves were minus on block and 2D mad unsafe.
Moreover, he ran out of range way sooner and easily than now since you couldn't reverse strings. IB being -5 could also reveal many gaps in his strings.
Things are just different, he's got new tools for pressure like DS DC for example, and his defence is still good as ever. You just gotta commit for good rewards now.