没错,句中的 all 为副词,主要用于加强调语气(used to emphasize how much better something is than it would be in a different situation),all the 在此表示“更(加)”的意思,后接比较级,句中通常有表示理由、原因的词语如 for, because 等。例如:
I feel all the better for the walk. 走路之后,我感觉更好了。
I feel all the worse for the medicine. 我吃下药之后,觉得更糟了。
The storm became all the more severe. 暴风雨越来越大了。