I would really like to see a better columns block. Columns are like a foundation of almost every created pattern, but currently it's very limited. It would be great to have more columns varations, changing column width by dragging it, change columns order on mobile without adding custom CSS such as flex-direction. Paddings and margings with breakpoints for every block are needed as well. I can find all these options in several block plugins, but such basic things must be in core.