How to remove the wrapper wp-block-group__inner-container arround the content of group ?

I am facing the issue upgrading from 2.9. Many styles are breaking because of this. +1

Just encountered this issue after upgrading as well. In my case, I had some grid layouts that turned into a single, narrow column. My temporary solution has been to add a style rule that just inherits most of the styles from the inner-container's parent.

.wp-block-group__inner-container {
  all: inherit;
  width: 100%;
}

However, it seems like this container was removed from the WordPress Gutenberg repository years ago, considering that its introduction caused problems back then, and it's only in consideration for legacy theme support. It should be removed, or there should at least be the option to remove it in some way.